I can see both sides of the issue here. It's sorta like fueling an airplane, you touch the clamp from the fuel truck chassis to the airplane metal before you let fuel flow. Electrolysis is an issue with metal pipe in the ground and no sleaving so you might not want it grounded. For safety in the house, it probably makes sense to ground it. All I know for sure is that I wouldn't touch the meter without bonding around it first, to make sure I would get any sparks because of a potential difference.
