Hi Mezcalmacy and welcome to the las vegas forum.
I'm not much into the club scene these days since I've grown out of it, but I made an online search and found a few places that serve Mezcals...
• Border Grill at Mandalay Bay.
• Buchon at the Venetian.
• Hotel California & Cantina Isla - Treasure Island.
• Jaleo Las Vegas at The Cosmopolitan.
• La Salsa at Ceasar's Palace.
• Mesa Grill at Ceasar's Palace.
• Petrosian Bar in the Bellagio Hotel.
• Star Canyon at the Venetian Hotel.
• Taqueria Canyonita at The Venetian Hotel.
• TT Tacos Tequila - Luxor casino and hotel.
And depending on your lifestyle, all of the above hotel-casinos are great for your stay in Las Vegas.
The Venetian has a few hotel towers with high star ratings and great cusine in most of their restaurants, plus a huge main casino.
You can take gondola rides in the Venetian canals, which can be romantic if that's your thing too.
Treasure Island is pretty nice too. I love watching The Sirens; they have two boats out front and put on a pirate play during certain hours of certain days (pretty exciting).
If your more in the mood for a quite moment; The Bellagio Fountains are awesome to watch too.
It's amazing to see how the fountains can shoot water so high into the air at the end of their performance.
I could go on and on about the above mentioned hotels and casinos, but I think you may get bored of reading about them before you get to the bottom.
I hope this helps you Mezcalmacy.