I've seen this question recently and seen rumors floated a bit about each. So I wanted to make a post about what is known with these rumors.
Eliza being nude in Banshee at this time is hope and pure speculation. The only real tidbit is last year she tweeted a reference to shooting a bare butt scene. What that will actually turn out to be we won't know til the scene airs. Aside from that she may have mentioned a lingerie scene as well or tweeted a photo of lingerie in reference to the show.
Melissa Rauch's character does indeed have a nude sex scene in The Bronze. However she is on record stating she used a double for the gymnastic portions of that scene. So until the movie is released wide I wouldn't hold out hope that she shows any nudity herself.
Hopefully on both accounts the current info proves wrong and we get great scenes from these beautiful women.