Yes

Hi, I have an annual season ticket from Banbury to London terminals which states is valid on all routes. Trains run to Marylebone but I needed to go to kings cross. I jumped on a bus...I wasn't sure if my ticket was valid but I have an oyster too. I showed the driver my ticket who looked at it, perceptibly nodded, and so I carried on. 10 mins later, ircas fine from an inspector. Do I have grounds for an appeal?