Originally Posted by gooselee

No experience with Virgin, but for all the big airlines personal accounts are just that - personal. DL for example, strictly differentiates between SkyMiles (miles earned for the specific individual who is flying) and SkyBonus (points earned for company based on spend) programs. To the point where individuals opening SkyBonus accounts without a legitimate business get their accounts frozen.

Short story: as other posters have said, if your friends set up their own FF accounts, it's a simple call to add their # to the PNR. You may even be able do this at the check-in counter or gate without blinking (DL will actually let you set up a new SkyMiles account and add the current flight on board while in air). But the FF# should match the passenger, not the purchaser.