As long as the accounts that are RAF are all in the same group you get 300% regardless of level. You can have an 85 and a 10 together and still get 300%. They have to be in the same group though, and summoning only works till 80.

I honestly think that leveling all the way to 90 and then starting back over is better. Makes it less brutal on the mind when you know every time you play a different set you gotta start at 80.