Quote from:
http://forum.warmane.com/showthread.php?t=65037
There is many types of powerleveling. You didn't really say what you meant with powerleveling, so all I can say to that right now is Powerleveling = bannable. Here is a little more detailed answer for the most common types of leveling.
Boosting: You get a high level character to join a group with low level characters and help those low level characters with their low leve instances/quests. This is totally fine as long as the mobs you are killing are not more than 11 level higher than the lowest member of the party.
Mob-tag-boosting: This is where you tag the mobs with your low level characters and kill them with your high level characters, giving the low level characters mroe experience than they should get. This is an exploit and you can be banned for this. This exploit is so common that the chances of being banned is most likely pretty low, because warmane most likely don't have enough resources to monitor this.
Powerleveling with bug: For example, finding a way to bug out some quest so you can complete the quest again and again and again and using that to level up. This is bannable and with a much higher risk than mob-tag-boosting.
You will not get a warmane answer to your question, because they don't want to give an answer. (You're not the first one to ask, others didn't get a reply, I doubt they want to answer to you either.)