Its 20 oz when Hot as Venti means 20 in Italian. Although for cold beverages its 24 oz. Same is for Trenta cup, as Trenta means 30 in Italian. Trenta cup is reserved for cold beverages in Starbucks. Trenta cup = 30 oz cold beverage.
A utility bill would be a bill for your water, electric, gas, etc.
utility - a facility composed of one or more pieces of equipment connected to or part of a structure and designed to provide a service such as heat or electricity or water or sewage disposal; the price of the house included all utilities.