... I drive a bus for the bus routes in the morning and afternoons. ...
I assume the school/school district pays you for being a secretary in the school and you probably signed some sort of contract that covers your work hours and pay rate. I understand that the “cheer sponsor” position is a volunteer position (albeit a position that comes with token pay).
But who is it who pays you to drive the school bus routes in the mornings and afternoons? The school? Or are you employed by a commercial or mass transit or some other company that contracts with the school to provide buses and drivers?
In other words, is your school’s bus transportation funded by the state through a transportation allotment applied for by your school and then your school pays you out of these allotted funds to drive a school district bus? Or does an outside company pay you to drive a bus owned by the outside company?
Whoever pays you to drive the students to and from school on the school bus
should be the one to okay any additional uses of the bus for transportation to the football game(s) and should be the one to pay you for the extra travel.
If your regular school bus route pay is funded through a state transportation allotment, use of the bus for extra curricular events or field trips (like football games) would not be an expense covered by the state transportation funds. The costs to operate the bus and pay the bus driver must be funded through some other method.
I think you are probably entitled to pay for driving the bus outside your normal bus routes but I
suspect the school is trying to limit expenses that the school knows cannot come from the state (or school) transportation allotment. I
suspect the school is hoping you will volunteer your services as driver so they don’t have to pay.