I've asked for this before and not gotten any response.
Here's what I do know for sure: Moonglow is SDI, Vesper is SSI. Those are only two I currently use.
Here are some of the city trade deals that existed in the past, but I don't have toons who have been citizens since the last election cycle: Jhelom: SSI, Britain: FC, Skare Brae: FC, New Mag: SDI, Minoc: SSI. All of those may have changed though.
Hope that helps.