During the epilogue, you play as Tavia wanting to recruit the five you played in the game to her community. It depends on the way to talk or play each characters story to have them join Tavia. Becca will stay with Shel no matter what. This is how to get each of the characters to join you.
The only way for Vince to join you is if you shoot Danny's foot instead of Justin's.
If Wyatt stayed in the car, he will join Tavia regardless. If he went to find the person, you have to say that they might find friends or family in the community.
The only way for Russel to join Tavia is to say he might find friends or family in the community.
Bonnie will always join Tavia no matter her choices or what Tavia says
Shel and Becca
If Shel leaves the Diner group in the car, they will join Tavia regardless. If not, the only way for them to join Tavia is to say there will be kids and adult of all ages.