Hi Stephen,
Sorry to hear about your diagnosis. If they've put you on hormone therapy (HT), this most likely indicates that the planned treatment will be radiotherapy (RT), which will probably be done after you've been on HT for six months or so.
There's no reason at all that you can't continue to work normally during HT. You'll probably need some time off while you're having the RT (which is administered daily, Monday to Friday, in either 20 or 37 "fractions") because it often causes side effects such as severe diarrhoea, which I imagine would be a significant issue for a bus driver.
I'd suggest that you download the information sheets about treatment of locally advanced prostate cancer and its side effects from this site, and speak to the nurses on the freephone number. They are very helpful and knowledgeable.
To re-emphasise, though, there's no reason at all that your diagnosis should mean the end of your working life. It's a very treatable condition.
All the best,
Chris