Is university transfer credit reported as S?
As far as I know, JET only requires you to be a graduate from a university, and having undertaken at least 12 years of formal education in English. Most of the shortlisting depends on well-written statement of purpose essays and cover letters are. Don't forget that you'll also need 2 letters of recommendation, and these will help to get you into the interview round where you can really shine and convince them why you should be on JET. If you're really worried about having the S/U notation in your transcript, be sure to include that you've gone on an exchange program to a different university - this could help you as well. But then again, if you can get transcripts from both universities, well... more information never hurt anyone. Good luck!