Lost water pressure in the hole house comes and goes. I have not done anything at this time. City states everything is OK at their end. Maybe I have air in the line / tank and all that has to be done is to bleed the tank?

Unless you live in England/Ireland/Europe, (they do funny things over there) or you are on a well system, you don't have a tank. If you are on a well system, what would the city have to do with your problem? There is no such thing as air in the lines of a municipal system in the US. Any air in a water supply line under pressure comes out as soon as a faucet is opened.

You probably have a pressure reducing valve (PRV) that is failing. It is most likely failing because of debris. Remove and clean the screen or replace the valve.