That's a good question. Also: Do followers of a pantheon generate the same amount of faith? I.E., if a worshiper follows a pantheon of six gods, does each god get one sixth of the worship? Or does he count as one believer for all six?
I'm also interested in the answer to AscendedMaster's question - is Prayer Power generated by people offering you an act of devotion? Do people just have to think about you?