So when we greet bishop Williamson we should kiss his ring and address him as ?
As I am an Englishman, I would say 'My Lord Bishop' or 'Your Grace' but I think the American form is 'Your Excellency'. Correct me if I am wrong.
I was under the impression that within the Commonwealth, a bishop is addressed as "My Lord," and an archbishop is address as "Your Grace." Perhaps I am mistaken.
In any event, in the United States, all Latin-rite bishops and archbishops are addressed as "Your Excellency," except for those who are also Cardinals, in which case they are addressed as "Your Eminence."