Currently, the filled maps does not support filled maps for Canadian zip codes. The filled maps work with countries, US States and US zip codes.
The following KB article provides information on which geographic roles are built in to Tableau:
Hope this helps!
Thanks for getting back to me so quickly, Tracy. I assume this applies to all versions of Tableau. The Symbol Map is still very informative and looks cool, so I'll run with that.
I've been informed this is a possible workaround, although you need the xy to each corner of the postal code in order for it to work. I haven't tried it myself, but that's a possibility.