There are a few recent updates to myVEGAS that you may have missed. The most important one is that the Monte Carlo is no longer a partner. The Monte Carlo became Park MGM on April 1, 2018 and the Rewards are beginning to catch up. Room Rewards aren’t available yet, but the usual assortment of dining, entertainment and FreePlay are now available under the Park MGM heading. Note that there are still some Rewards under The Park (not Park MGM, but The Park), for some of the restaurants at The Park.
Wedding packages are starting to appear as myVEGAS Rewards.
I noticed the Luxor’s “Just Between Us” Reward a while ago, but now there is a $200 off weddings at MGM Grand as well. I haven’t pursued the details, but the price for the Rewards seem very reasonable.