It is not common for banks to withhold taxes on your interest earnings. It's also not common for taxes to be withheld on U.S. Treasury Bonds. But if taxes are withheld, they will be shown in box 4 of the 1099-INT. If your state taxes personal income and taxes were withheld for your state, the withheld amount for the state would be in box 17 of the 1099-INT.
