Few bikers in Las Vegas. Either too hot or too cold. I can't think of a big bike club here.
The only place I've ever seen bikes congregate is at the Mountain Springs Saloon on State Route 160 on the way to Pahrump.
If you're riding, take the long way out Charleston (State Route 159), past Red Rock National Conservation Area, turn right on Blue Diamond Road (State Route 160) and go to the top of the mountain. The saloon is on your right. Return to town on Blue Diamond Road.
Mountain Springs Bar
Mountain Springs Rd, Las Vegas, NV 89101
Very cool place. I did it on a summer sortie in a 5.0 Stang with top down, fast. The dry air sucks the moisture out of your body like a vacuum, bring lots of water. It's a little more comfortable when you get to altitude, and a very scenic panorama of the valley on your return.
This is too obvious . . . but there is, of course, the Harley Davidson restaurant! I've actually eaten there, and it's fine if you are looking for burgers, steaks, ribs, fries, salads. It has a sort of chain-like feel to it; no real artistry or technique evident in the menu. But it will fill you up, and there are lots of Harleys to look at.