you can create a generic trigger with events on enter/ on exit that only will be applied to wiz/sorc
script on enter (your zone)
if(GetLevelByClass(CLASS_TYPE_WIZARD, GetEnteringObject()) >= 1 || GetLevelByClass(CLASS_TYPE_SORCERER, GetEnteringObject()) >= 1)
{
your stuff
}
also you need to create the script on exit to remove the stuff