I have been to the FR in Vegas a couple of times. A friend of mine was staying at Mandalay Bay, and got us 1 night access from the person at the Priority Line/VIP check in area. I wasn't into rewards/points/perks at that time so I wasn't paying attention, but I believe it was tied into his Mlife tier status.

The last time I was there (last year) the FR was kind of dead, but I am going to Vegas for the consumer electronics show, so I will see if I can get access the FR on my own. I have the Hyatt Card from Chase which gives me Hyatt Platinum Status, which gives me Mlife Gold tier status automatically, and access to the Priority line/Vip check in area at MB.

If I get no love from being Mlife Gold, then I believe I heard (on yelp?) that if you do a dinner reservation that will give you access also. We'll see.