Did Jesus mean a truly spiritual man should feel this rewarded NOW, or in the world to come? Mark 10:28–31 (NKJV): 


  Then Peter began to say to Him, "See, we have left all and followed You." So Jesus answered and said, "Assuredly, I say to you, there is no one who has left house or brothers or sisters or father or mother or wife or children or lands, for My sake and the gospel's, who shall not receive a hundredfold now in this time—houses and brothers and sisters and mothers and children and lands, with persecutions—and in the age to come, eternal life. But many who are first will be last, and the last first.” 


Note the "now in this time."

Should Christians feel worried if they do not feel spiritually rewarded to that degree in the present age? Or did he mean through the hope of the true joy... that is in "the age to come, eternal life"?
What Jesus was doing is telling his disciples that they would become a child of the kingdom, but since they were pre new testament and pre crucifixion, they would have no understanding what the Kingdom of God really referred to.
Remember that these men were under the impression that the Messiah; whom they believed Jesus to be, was going to set up an earthly Kingdom, and a Heavenly Kingdom would never cross their minds until Jesus had arisen and they realized that Jesus was much more than just a man.
So let's us take a look at Scriptures and see if we can determine what Jesus really had in mind.
Once Jesus had been resurrected from the dead the true meaning of the kingdom of God was understood, Paul said in his epistle to the Romans:

Romans 14:17  KJV  For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost.

Even though Jesus had on many occasions tried to explain the Kingdom of God, not only to his disciples but also to the crowds as indicated in the following Scriptures: It was not ever grasp by any of them until his resurrection.
Matthew 13:24  through 33  King James Version

24  Another parable put he forth unto them, saying, The kingdom of heaven is likened unto a man which sowed good seed in his field:
25  But while men slept, his enemy came and sowed tares among the wheat, and went his way.
26  But when the blade was sprung up, and brought forth fruit, then appeared the tares also.
27  So the servants of the householder came and said unto him, Sir, didst not thou sow good seed in thy field? from whence then hath it tares?
28  He said unto them, An enemy hath done this. The servants said unto him, Wilt thou then that we go and gather them up?
29  But he said, Nay; lest while ye gather up the tares, ye root up also the wheat with them.
30  Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.
31  Another parable put he forth unto them, saying, The kingdom of heaven is like to a grain of mustard seed, which a man took, and sowed in his field:
32  Which indeed is the least of all seeds: but when it is grown, it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof.
33  Another parable spake he unto them; The kingdom of heaven is like unto leaven, which a woman took, and hid in three measures of meal, till the whole was leavened.

So let's take a look at the first parable see how it applies to your question. the first parable is contained in verses 24 through 30.
Let's start with verse 24 and 25. Jesus is likening the Kingdom of God to the world.

God created the world in a perfect state and Satan introduced havoc in it, then went happily on his way.

verses 27, and 28.
Here Jesus is telling them that when God talked to him and the Angels they asked if he wanted them go directly to the end times and begin the judgment.
verses 29 and 30 are his answer.
He told them that  no otherwise when the evil ones were destroyed those who would accept Salvation would also be destroyed. So he would wait until  the proper time and then separate the righteous from the unrighteous.
In the second parable verses 31 and 32:
Jesus is telling us that even though the Kingdom of God would start with just those few followers there; that it would grow to include many people from many Nations.
And in the third parable verse 33:
He is describing the spread of the Gospel from Jerusalem throughout the World.
So to answer that part of your question about when, the answer is that he was trying to tell them once they entered into the Kingdom of God they would again enjoy the companionship with God lost by Adam and Eve in the Garden of Eden and that once  the Kingdom of God was established through his death and resurrection they would again be a part of the family of God in which all would be of common status.