#7 - Sept. 21, 2010, 10:46 p.m.
Bullchanon is correct. As long as you all are within 4 levels of each other, grouped, within close proximity to one another and killing mobs/completing quests that are not considered to be trivial to anyone in the group you'll receive the Recruit a Friend bonus.
As Eilethalua pointed out the triple experience does not stack and it only applies between the accounts that are directly linked. So if characters from Account A and C group without B they will only receive normal experience.
Good luck to you, Corvi, if you haven't already please check out the following FAQs on the Recruit a Friend system.
Recruit a Friend FAQ
http://forums.worldofwarcraft.com/thread.html?topicId=8765628748&sid=1 http://us.blizzard.com/support/article.xml?articleId=20588