I've had 3 different male bettas with my gold gourami, and he's never fought with any of them. I've seen the gourami picking on my swords now and then, but never any of the bettas.
I've got 30 hex with a gold gourami, a big blue betta, 4 swords, 4 ottos, 5 panda corys and 7 rasboras, and the betta is actually the only thing I haven't seen the gourami nip at.
Well, my last betta got constipated and died, and the day he died he was having trouble swimming, and the gourami did come up and poke at him a little bit.
It seems like bettas and gouramis can have very different personalities from one to another, and you really can't say for sure what they'll get along with. You can say that bettas will attack other bettas and gouramis will very often harrass other gouramis, but other than that I don't see a lot of consistancy in who they get along with.