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.
Your energy bill is a monthly snapshot of how much electricity you used in the prior month, along with how much you must pay to keep the lights on for the next month. Beyond that, if you know where to look, it contains some useful information regarding your energy usage and energy rates.