I would bet. I'm not giving away free cards with both flush and str8 draws, let them pay for it, plus you might want one of them to fold to narrow the playing field. Raiser could be sitting with AJ(perfect), AQ, QQ+ and even reraise you.
I often go for potsize bets here, because I worry about them completing their draws. I know that isn't the way to get big pots, but I hate going on bad beats knowing I could have taken it down there and then. Hindsight, that lovely goose.