George, what you describe is all to common, whether the appliance be a Ham radio, an antenna, a satellite dish, cable TV, or the phone box.
As I understand it, this grounding is simply there for lightning protection, and not in any way associated with clearing a fault current.
I would think that, were faults an issue, the thing would have a three-prong plug.
Even so, I believe code requires all grounds to be bonded to each other, while being pretty vague as to what this might mean. I've certainly never seen one of these things capable of accepting the #8 wire we're required to use here (for bonding pipes to the ground system).
As long as there is continuity between this wire, and the grounding system, I'd say he's met the requirement.
