Hello,
He's not listed as a Knight of the garter (1348-present day). i checked the list at
http://www.heraldica.org/topics/orders/garterlist.htm#list
which is a List of the Knights of the Garter, 1348-present
You may have to check a few other heraldry sites to get an answer though. If you click on the sources link on that page it will give you several other resources to check regarding knighthoods.
Yo may be best to direct your question to The College of Arms ( http://www.college-of-arms.gov.uk/ ) as they are
The College of Arms is the official heraldic authority for England, Wales, Northern Ireland and much of the Commonwealth including Australia and New Zealand.
As well as being responsible for the granting of new coats of arms, the College maintains registers of arms, pedigrees, genealogies, Royal Licences, changes of name, and flags. The heralds, besides having ceremonial duties, advise on all matters relating to the peerage and baronetage, precedence, honours and ceremonial as well as national and community symbols including flags.