I was very surpised to get an e-mail at the end of August saying that my
Oyster card had been topped up "on bus route 76". I set the card up for
auto Top Up when it first came out and haven't done anything since so I
suspect that once you have auto top up setup it now works on buses (as
well
as tubes).

Indeed it does. It was launched a few months back without an awful lot of
publicity which slightly surprised me as it was a big step forward for
Oyster. At the same time it officially started working at tram stops too
having already been working for a month or two previously. It also then
became possible to nominate a tram stop to collect online top-ups and auto
top-up instructions as well as tubes and DLR.

G.