Originally Posted by
ruckzac
I completely agree that it is far preferable to get upgrades confirmed at the time of ticketing vs. day of departure. However, this is always subject to upgrade availability, regardless of instrument used to upgrade (certificate, cash, or miles) for both Delta and Virgin.
I see no reason why the flight would need to be credited to VS simply because FlyingClub miles are used as a method of payment to upgrade a flight.
AFAIK you must associate the FF number to the flight from the program whose miles are being used for the upgrade. SkyTeam doesn't let you use one FF number for status/benefits while crediting to a different program. In fact, there have been reports of people losing free elite upgrades on DL flights if they change to an AS FF number.