As far as i can tell if your willing to AoE a spell that applying the aspect, each person who gets the effect should get a free tag of it. Think something along the lines of group telepathy, applying Perfect Team Work, or some kind of Reverse Entropic Effect, Amazing Luck. In the end it will be GM call, i'm certain plenty of folks will look at this and go No wai!!! and say that you need to spend for any use beyond the first. But it is a good idea to motivate wizards to do something other then Swing as big a magic attack as possible, Giving your whole team a free tag is most like easily as effective, and way more group friendly.