The way i got it explaind to me. Account A that you use to boost with needs to be unlinked. Account B referes Account C = These 2 will get the RAF bonus.

If your not boosting then you can do it like this. A > B > C. and all 3 will get 3x XP

You should be able to use Account B-C and lvl to 60, then lvl Account A-B to lvl 30 and grant them to lvl 60.

Anyway, wish i was better at the explaining part..