I grinded TI quite a bit during my Vegas stay and I can say its not worth it for the most part
Most people play extremely shortstacked, the rake is awful, and most of the regs play a very nitty style. I spew pretty hard in these types of games out of boredom so I stay away
However, I will say that some nights between like 11pm-5am, I played in some of the best 1/3 games I've ever played in Vegas at Treasure Island. You'll get a lot of random people who are staying at TI and just come down to gamble at poker.
I would just grind at Wynn and then take a quick walk over to check out TI. I think they're promotion is really good if you are trying to build a bankroll because you'll play in very low variance games and make $10/hr in guaranteed profit.
Good luck!