Huh? A couple of problems ... some with the pic, some with the post.

If it's not the main panel - neutral buss should not be bonded to the panel. The ground wires need a separate buss - and are always bonded to the panel.

Feeders get a separate ground wire ... an insulated one ... period. (Well, not quite .... the ground wire need not be insulated if a cable, like SER, is used as the wiring method). Whether you need a bushing is determined by the wire size alone - not what it's used for. You don't get to use the pipe as your ground wire for feeders - only branch circuits.

So, how do you know something is a feeder? Simple; it has a breaker or fuse at the end of it. A branch circuit has no breaker or fuse after it leaves it's source. (That's the short version).