I phoned BD over a year ago and asked for my BA G to be matched and they said no poblems. I filled out the application form and sent it in with a small cover fax and a copy of my statement.
My BD G card arrived in about 10 days and was valid for a year. I managed to earn enough points for this year in about 3 months.
I only wanted it to comp my UA *G card for lounge access when on US domestic flghts down the back of the bus.