Short answer, yes.

Longer answer below.

Each account linking, needs to fulfill a few conditions for both to get the RAF bonus.
When A -- B are linked, they need:
1) To be within a +/- 4 level spread of each other;
2) To both be level 59 or lower;
3) To have the mobs not be grey to either account;
4) To be within a certain range of each other;
5) To be within a certain range of the mob as it dies.

In your case, you have:
A -- B -- C
And "A" is the booster, so the A -- B link will not work for B getting the bonus.
However the B -- C link is just fine, so B and C will both get RAF.

And if you were to create a lowbie on A.
Then the A -- B link would probably be fine too, which would have all the toons getting RAF.

Even with A as the booster always, and never getting RAF.
Because you linked from A, B will grant some levels to A as well.