The music at V Bar is usually hip hop and it's never too crowded. I would say V Bar is a secondary destination for those that either couldn't get into Tao or didn't want to wait in line any longer. I usually go there to pre-game or support the DJ. It's a good-sized lounge and the bar is nearly the length of the room.
There is a dress code but if you're out on a weekend, then you should be in character already. Not the greatest place to conduct business, but transactions can be made--especially after 2am.