Join Date: Apr 2009
Location: Bye Delta
Programs: AA EXP, UA Silver, HH Diamond, IHG Plat, Hyatt Plat, Marriott Titanium, Nat'l EE, Avis PC, Hertz PC
Posts: 16,614
I have been able to upgrade a companion on a separate reservation essentially every time I've used an RUC, despite the language on the cert. As long as that person has been on the same flights, it's been a non-issue. (Though the last time I tried was a year ago.)
No way to upgrade more than one companion though. You + 2 companions isn't going to fly.