I have looked up the roll for the DFC and there is a Flight Lieutenant R.M. Bayley of the Royal Air Force listed (awarded in the New Year Honours of 1919) but with no DFM or foreign orders that I can see. However, I recommend that you look up his service record at the Public Record Office, Kew, London. This should confirm what his entitlement was.
Take a look at the Western Front Association's research pages for advice about how to look up details at the PRO. The URL is
http://www.westernfront.co.uk
Best wishes,
Jim