Paul wrote:

As the Victoria Line is closed tomorrow, what is the situation
regarding people with Oyster PAYG and getting on a replacement bus? Do
you have to touch in on the bus, and if when you do get on the tube
does the system recognise it as one throught journey.

The other weekend when I was on a replacement bus for part of the District line,
the driver said not to touch in. Basically the replacement bus portion of the
journey was unrecorded.