If A is the booster, and your set up is:

A -- RAF Linked to -- B
A -- RAF Linked to -- C

Etc.

Then none of the toons will have a working RAF, since each is only linked to A, and A is the booster.




If however you go with:

A -- B -- C -- D etc..

A can be the booster.
And B still gets RAF because B is linked to C.



To get RAF bonus, you need:
a) To be directly RAF linked to an account you are grouped with; and
b) To be within +/- 4 levels of that account; and
c) For both of you to be level 59 or lower; and
d) For the mob/quest to not be grey to either toon; and
e) To be within a certain proximity of the other toon.

The A (Booster) -- B... Link does not qualify B.
However, the B -- C -- D -- E.... Links (all toons being boosted) do qualify.
So they all get RAF.
B on the basis of the link to C.
C because of the links to B and D.
E because of the link to D.