I have a main breaker box that would be considered a sub panel.(Main shutoff outside on pole) The box is a New Square D Home. The common and ground bars are bounded. It is my understanding the common and ground must be separate in the case.If I am correct, what is the best practice and code for the bare ground wires.

Only at the main breaker must the neutral be bonded to the equipment ground. The feeder from the main disconnect to the circuit breaker panel must have 4 wires, one insulated for the neutral and one insulated or bare for the equipment ground.

Downstream of the main breaker, the neutral must be insulated and isolated from all bare or green equipment grounds.

At the panelboard a separate equipment ground bar is needed for all green and bare grounds, and the bar is bolted to the metal can of the panel using machine thread screws.

Not sure if this answers your question.

Why are you thinking it's a sub panel? Every panel has a mean of disconnecting at the pole. Does this panel have a main breaker in it as well?