Earth NYC or 49 Grove?
I've been to both but not for dinner only drinks and dancing. It really depends on what you are looking for. Earth is a big draw for the Indian crowd and has some interesting drinks. 49 Grove can get really crowded and the drinks just ok. I would do dinner somewhere else in both cases...
I went to dinner at Earth NYC - I dont' remember it having dancing though. Food was good, timing of it all was so off - the waiter was horrible, but the manager was great and comped our entire dinner. So I give it a so-so.
I have also been to 49 Grove for drinks and dancing, I think this would be a better bachelorette spot. Not sure about food though, but this place seems to have had a fussy door. Perhaps not if you have reservations.
If you eat a late dinner, I think Buddakan and Lotus (both in Meatpacking) turn their restaurants into clubs after dinner. These might be some good options to consider.