To the OP: regardless of the Amex points earned, you should always charge all restaurant spend at MGM properties in Vegas to your room anyway, because:

1. You can earn Hyatt points for your room bill at MGM properties, including for any restaurant charges or other incidentals charged to the room
2. You also earn Mlife tier credits for your room bill and incidental spend, and if you pick up a couple of decent-sized restaurant bills it can even be enough to get you a lot of the way to the first couple of Mlife elite tiers -- which then themselves come with various room discount offers and other benefits, even if you don't gamble at all

Note that you can charge restaurant spend from any MGM property to a room in any other MGM property, so you can charge a restaurant at the MGM Grand to a room in the Bellagio, etc.