I think we have to assume that Bryant brings something to the table that the locals don't, and the consensus seems to be that it is his white face. There are certainly plenty of good English teachers with Asian faces, but I think we also know that there are some terrible English teachers who are not native speakers (like the 'million dollar' English tutor who was sued by his school - and who insisted on the Court Proceedings being conducted in Cantonese because he didn't understand English well enough). Perhaps it simply reinforces the prejudice of the locals but clearly, Bryant's presence makes his employers more money, ergo, he is paid more.