Thanks for the feedback. So far that's not happening on mine, but I had to reset the upload settings on the iPhone, so it might be busy trying to up,lad all the photos before it syncs the favs.
Now that I am on my iPad, I just looked and mine are synced. I just favorited one on my iPad, and it is now marked as a favorite on my iPhone. So, if it is not working, something is stuck.