I think this tool will allow you to find the VISA merchant classification, but you will need to know the location of the business and (perhaps) their real name which might be different than their trade name:
http://visa.via.infonow.net/locator/...tLoadAction.do
The tool is really designed to the opposite (find a particular type of merchant), but I suspect you can play with it for this purpose.
I was able to find groovetickets the main one I'm looking for. "GENERAL MERCHANDISE -5999" Not sure where to go from here though, I don't know of any card bonuses that would help maximize it. I did learn some new stuff though. It makes sense for the categories it's showing up in, though.