i hardly believe that they would ban you for tagging targets out of your mains party Athene got hit because well i guess how noticible it was at the time (people reporting him) despite getting previous clearance before WOTLK launch... no one is going to report a group of five doing that... heck most people prob wouldn't even know your main wasn't in party with your other four (i say this because i used the raf'd shammy team i was lvl'ing to quickly get a new priest to 70 to get the merrymaker title... ) bottom line if u tag the target, and the mob is at least green to your non partied alts and not orange to you... you will get full xp.

that type of tagging has been known and being used for years athene was an obnoxious exception to the rule.