Great. You should be good to go. And being SPG, you should get stays and nights for all three rooms in addition to all the points for allowed room charges. By having the other guests on the rez will allow them to check-in before you, but do ask when you arrive that everything is still set up for you to get credit for all the rooms. Some agents get pretty aggressive trying to sign up new members and they will automatically change the room to the new account.