For those using Public Transport in Oxfordshire (which includes much of the Cotswolds most visitors go to) there is a new all operator daily and weekly bus ticket- MyBus for £6.50 daily or £25 weekly (any 7 days).-
https://www.mybusoxfordshire.org.uk/mybus-oxfordshire-tickets
It is also valid on through services into the surrounding counties of Warwickshire (for Stratford on Avon), Berkshire (for Reading and Newbury), Gloucestershire (for Cheltenham) and Buckinghamshire.
As they are not local bus services it is not valid on the Oxford Tube to London, the Airline to Heathrow and Gatwick or the X5 to Bedford and Luton Airport.