some of them may not be open for a few more weeks, but....
venus at caesers palace
Bare at mirage
moorea at mandalay bay.
all toptional pools. if the bottoms are sheer and really obvious idk how they will feel about that.
You can wear sheer at the Hard Rock but not topless. At least that's the way it was during Halloween weekend. I'm not sure about during Rehab.
Sapphire's has a pool that I believe is topless