GFI breakers and regular receptacles would be the best bet, for just the accessibility reason you stated.

The #8cu solid DOES NOT have to go back to a service panel. it is a BOND, not a ground.
The #8 has to connect to the motor, heater housing and any metallic water pipes associated with the tub.

I just did one this week with all PVC piping on the tub and all PEX feed lines. The #8 went from the motor lug to the heater lug. That's IT.

Thanks, Petey Racer, for the info. But it leaves me a bit confused.

In your situation, if there hadn't been a heater, would you have bonded the pump to any thing?

Guess I need to school myself on the difference between bonding and grounding. I have considered them to be similar. In this case, I thought, that bonding the pump and heater housing with the copper wire gives an errant charge in the housing a path to follow, hopefully away from a person in a tub of water.

I just read the thread "bonding vs. grounding. I'll read it a few more times, and I might get it.

Thanks, you people are great!