Basically, if you want to show d3
and tableau
together you can embed a tableau visualisation along with a d3 visualisation on the same page. Looks like doing it with an iFrame is popular.
Also, note that the way iFrames work with tableau have changed a bit over time, but here is the latest update (March 2014) from them: http://www.tableausoftware.com/public/blog/2014/03/fix-your-iframe-2386