Originally Posted by
javabytes
You cannot combine your reservations. Technically you must be on the same reservation to apply an RUC or GUC to a companion as per the T&Cs, but I and many others have had success with separate reservations.
This is not true. You can apply an RUC/GUC to any person traveling on the same flight as you. If you are both booked in Y, upgrade space could be available for you and a companion. If you paid for the premium cabin, you can apply your certicate for a companion outside of your PNR.
For example, in two weeks, I'm flying JFK-HNL. My husband and I booked in one PNR JFK-HNL in Y. Our friend booked his own reservation in Y on the same flight. I used three of my RUCs to upgrade all three of us at booking (inventory was available).