There is a reason to periodically sanitize water plumbing in your RV. If water is allowed to sit in the pipes, pump, or water heater, there is a chance of bacteria propagating. Depending on the water source, there may also be a chance of algae growing. Adding bleach to the water system is easy and painless and a whole lot of bleach isn't necessary. Bleach's sanitation qualities are related to the time after it is mixed with water. Allow at least 12 hrs of the bleached water to sit in the system. Then rinse. You can also add in baking soda or hydrogen peroxide to eliminate bleach taste and odor during the rinse.
Good luck with your water system!