However before I went through the barriers to the overground train I discovered my last train had gone. Between there and the tube my AppleWatch ran out of juice! Lucky I had not swiped in!
Therefore I had a chance to use ApplePay on the iPhone 6 Plus. I didn't realise the NFC field would activate it, so I opened Passbook and fiddled for a while, as I couldn't work out how to make the card ready.
So I just placed it on the contactless reader on the gate and put my finger on the scanner. It took a while and was rather cumbersome, but it did work, and on the other end too.
Love the AppleWatch ApplePay tibe/overground/tfl experience, but I shall be avoiding doing it on my phone whete possible.