If I Scanblast an Infernape Lv.X with Metagross EX and the opponent also has a normal Infernape in bench does Scanblast also do &0 damage to that Infernape. (since its suppose to be the same name)
It's not supposed to be the same name, it is the same name.
The Level of a Pokemon is not part of the name, including Level X Pokemon.
Scan Blast would affect the benched Internape.