Yes, you can use your bus pass in London! Don't make a show of yourself by trying to tap it on the onboard ticket machine, though, the buses don't recognise the Old Dears' bus pass, you just wave it at the driver and smile. When I visit my daughter in London, I get the 68 bus from Euston to Herne Hill, it takes about an hour, but I love seeing all the stunning buildings, and the view from Waterloo Bridge as we cross the Thames. The daughter makes fun of me, because it would be much quicker by Tube, but it's a free journey (and sight seeing tour), so I'm damn well using my bus pass!