Iala
No. One of the primary reasons why healbombs are so vital in OPs is that the splash from other teams is instrumental in keeping one or two members of a struggling team up long enough to rez their teammates, or supporting the only one or two mages in a largely melee/ranged team. Restricting healbombs to team members only would gimp the heal mechanic entirely.Better solution would be for the heal bomb to bounce only on teammates (I think it does this already, but I may be mistaken) and make it impossible for people in the same team to be flagged differently.
Restricting healbomb splash to flagged allies, during PvP, would be a sensible partial solution, however.