I am contacting you about this profile: Sir William Bannester
I attach a pedigree in regard to an Alexander Bannister, who lived in Belton, Lincolnshire. The Pedigree has him as being the 9th son of Bannister of Bank, Lancs.
http://www.mocavo.co.uk/Lincolnshire-Pedigrees-Volume-50/498057/185
Alexander also married an Ann Standish of Standish Hall.
It would appear that this Alexander may be the brother of William or possibly an uncle. I don't know if there is anyone who might have further information re. this family to help identify where he would fit into William's tree. The term "Bank" is one that seems to be repeated throughout Bannister family pedigree and undoubtedly relates to their family home.
Clearly if Alexander is a 9th son, then there must be many more siblings.