New England Historic Genealogy Society has been putting online information about the settlers of the Beekman Patent in Duchess Co., NY. Amongst their latest is information about the Banckers, some of whose descendants eventually changed their names to Bunker. The information is published in THE SETTLERS OF THE BEEKMAN PATENT, DUCHESS COUNTY, NEW YORK: AN HISTORICAL STUDY OF ALL THE 18TH CENTURY SETTLERS IN THE PATENT. It was published in 6 volumes between 1990-2001 and you may be able to find it in a library someplace. The Bancker information is in volume 2 and I have copied it. Bette