What clubs can you get caps for?

I got one in the twilight club :o but other than that i don't have caps in any other clubs, sorry

There aren't very many. Fanpop itself wants to give you the caps for joining them for no reason because of money or for the sake of spamming you with ads every first time you check your inbox every day. I don't know what the reason is, but I'm sticking with those two possible reasons.