In what way was Isaac's blessing on Jacob manifested? In Genesis 27, when elderly Isaac thought he was blessing his son Esau, but he was actually blessing his son Jacob through the deceit of Jacob's mother, he said to Jacob:


  See, the smell of my son is as the smell of a field which the LORD
  hath blessed: Therefore God give thee of the dew of heaven, and the
  fatness of the earth, and plenty of corn and wine: Let people serve
  thee, and nations bow down to thee: be lord over thy brethren, and let
  thy mother's sons bow down to thee: cursed be every one that curseth
  thee, and blessed be he that blesseth thee (Genesis 27:27b-29).


My Bible commentaries don't explain how this blessing was borne out. What do Protestant or Catholic authorities say about how this blessing was fulfilled in Jacob's life?
It's important to keep in mind that the stories about the patriarchs are both stories about individuals and "national origin" stories giving an identity to the whole nation of Israel.

So in the case of Jacob (also known as Israel), the promises get borne out (a) in his great success as a herdsman for his uncle Laban, accumulating a huge amount of personal wealth, (b) in his victorious return to Canaan with numerous wives, sons (who become the twelve tribes of Israel), and servants, (c) in Laban being forced to begrudgingly accept the loss of his most successful servant and his daughters/grandchildren (his attempts to curse/foil Jacob only come back to bite him), (d) in the lives of his children, particularly Joseph, who has a very similar prophecy about brothers bowing down made about him (Genesis 37), and who becomes the vice-ruler of Egypt, resulting in nations bowing down to him as well, and (e) in the nation of Israel itself, especially in its relatively short lived hey-day of regional power over some of its smaller neighbors (David and Solomon's kingdom) before the kingdom divided and eventually went into exile.