Here is a guest post about bus travel in Reading from a local resident:
"We are so lucky to have the number 17 bus route serving our area - I know of no other service quite as frequent and regular as the 17 anywhere in the South East. However, since I don't have to use the bus daily for work, the one minor irritation is that I have to have the exact amount in coins to use it. If you also find that a deterrent, could I recommend the Smart Card.
You can get one from the Broad Street Mall (Reading Buses kiosk is outside Julian Graves) and put money on it using your credit card. Your balance is then called off each time you ride the bus. Fantastic - no more scrabbling for change - and I gather you can top it up in cash on the bus itself, or at a number of newsagents including Guru newsagents on the Wokingham Road.
I'm a late adopter of this technology and I didn't find the details on the website very clear but the staff are very helpful at the kiosk and it's a great way to fund odd trips to town."
I talked to the bus company and they said that any shop displaying the "PP Paypoint" symbol should be able to top up your card. There is more information here including a way to search for your nearest top up point.