Got the same question. Have 4 DVC exchange certificates that I'm going to use in november.
I'm nervous to link them as I don't want to screw them up.
To the previous poster, you need to create the other members in your travel party. Then you can link the individual tickets (I think) to different individuals.
I wish I was a few months before, or after, this fastpass+ thing. I prefer to know what to expect and let them work out the kinks. Seems like my trip may be right in the window of the switch over. If it was just a small group, no big deal, but I've got a party of 13, and for 9 of them it'll be their first trip.