The are limited ways to implement this. you can:
-Add a 9th slot to raid groups, and a 5th to dungeon groups
-Allow the buffs to enhance the other DPS by the value of 1 entire DPS player
-Allow the bufs to enhance one healer by the value of 1 healer player

This is especially problematic as you will end up with:
-27 man CT's (yikes! i run away from 24 man, no need for more trolling, thankyou)
-5 man Dungeons, with one slot reserved JUST for BRD (that'll make queue times even longer)
OR
-You'll end up with a 4-man party that has 1 BRD, and less other DPS to buff up to make requirements, also if that other DPS is undergeared, it would devalue your BRD
-he is buffing a healer instead of DPS, and the dungeons are tuned for 2 DPS.

So no, just no, absolutely no no no.