Bob,
I agree with you that the hot and cold water must be bonded together but not at the water heater. If I was inspecting a job and I don't see the jumper wire at the water heater, I would try to look at a boiler or washing machine to see if there is a connection between the two. However for the $5-$7 dollers worth of parts for the bonding wire and clamps, most guys just throw it on. Also if the bonding jumper isn't at the water heater and it is bonded elsewhere, sometimes it is hard to find out where it is bonded. Some AHJ's might not take the extra time to try and find out where it is bonded.
