Originally Posted by
NYCflip
Call your medallion line. You should be able to link your PNRs for companion upgrades. I have flown with my sister on separate PNRs and have been successful in linking our PNRs and getting upgrades and/or EC seats. Only possible if you call.
No companion upgrades if the companion is on an award ticket, unfortunately:
https://www.delta.com/skymiles/about...jsp##companion