Does air trapped in water pipe disturb the meter reading?
It is a long time ago since you posted your comment, but I will answer anyway, as I believe it can help many people. I live in Brazil, and here we have had many issues like you described, due to changes in the pressure of water supply company. It makes that much air comes into the piping, and when this trapped air comes to the home meters, it is registered as a normal water flow, and you pay for it.
Some small companies here have developed a kind of a valve that blocks this air, and keeps it trapped before your meter, while permitting the water to pass. This is reducing the water bill for almost 50% in some cases.

Please look for "bloqueador de ar". I did not find nothing like in english language.

Hope it helps, and good look!
Paulo