Should my wife wear the Hijab (Veil) in the presence of my foster father?
Your foster father is regarded as your father, so your wife does not have to wear the Hijab in his presence acting upon the saying of Allah (Exalted be He):
...the wives of your sons who (spring) from your own loins
This includes the wife of the foster-son according to the saying of the Messenger (peace be upon him):
Foster relations are treated like blood relations (in marital affairs).
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.