Hi again TaKelly!!
We are actually having our group meet up at the Lobby Bar on the Sunset Side (I'm sure you will be on the Sunset Side since the Platinum Suites on the he Riviera still haven't been repaired after last year's accident). The Lobby bar is actually really awesome! It's an open air building (with a roof of course) has a ton of really of cute couches, tables and loungers. We tried out both the Sunset and the Riviera Lobby bars and we found that we liked the Sunset Side better as it had more of a Lounge feel.
If you didn't want to do the Lobby Bar, you can go to this Bar that has the Live music every night. This is a REALLY cute area that is right in the middle of all of the ala carte restaurants. I love this area because it is really fun and lively but it can get really crowded at night so people in your group might not have a place to sit down.
Let me know if you have any more questions!