That's pretty much it, unfortunately. The only other I haven't been to is Townshend's Alberta Teahouse. They get their teas from J-Tea, but I don't know what they get and doubt they get the really good stuff (or know how to brew it).
For Tao of Tea I would say to try the Chinese Gardens; if nothing else, the atmosphere will be nice.
If you're into the spiritual stuff then you can get/catch a tasting at Heaven's Tea - http://www.heavenstea.com/
(He does semi-regular group events, but you can also schedule something private.)
The Japanese Gardens does Japanese tea on occasion, but I don't think that they have a regular tea house that you can visit any time. Check their schedule: http://www.japanesegarden.com/events/summer