According to the Post Cereal website, the name is believed to come from the "grape sugar" that formed while baking, and the "nutty" flavor that they had. See related link.
The term 'grapes of wrath' is a biblical allusion. There is no one element in the story that corresponds to the grapes. It is referring to a passage that talks figuratively aout God judging the...
I have grown up in a grape growing region and have never seen a flower on a grape vine. The "baby" grapes are small nubs on the vine, but don't flower. If you have a vine with a flower it isn't grape.