Hi Dave S I organise the AG shuttle bus service for First Bus on behalf of Ashton Gate.
The level of service is dictated by the fixture , so for the game on Friday 26th Jan there will be 4 buses scheduled to depart from Ashton Gate , Winterstoke Rd. The first is scheduled to depart at 2200 but will leave when full. Then approximately every 10 minutes or if bus is full. These buses will then return for departures at 2245, 2300 & 2315. All this information relates to a 1945 kick off. For 2000 kick of the times are 15 minutes later.
Hope this helps?