Filled map is not supported by default in the current version of Tableau (6.1, see this post in the Tableau).
However, it can be implemented through the Polygon Mark (see for example here). The background map comes directly from Tableau and for Australian data, Tableau does not good job converting postcode into longitude and latitude (an example is here). What lack are the boundary polygons for each postcode area.
Filled map in Spotfire is probably the most easy one. In Spotfire, you could import a shapefile directly as a data table. Then you need to link the area id in the shapefile with the area id in your feature data table. Here is a screenshot.