Hi,
I did a search for Bertie on the 1911 Census (on Genes Reunited) with the additional forename of Frederick and one entry resulted.
As I don't have a subscription to Genes Reunited I can't give you any more details about Frederick but I suggest you investigate this further.
The details I did receive back about Bertie are:
Born in 1902; place of birth Surrey, Dulwich; location in 1911: Bromley.