I don't think that the number of tax courses matter really except for school that require thresholds for admission like GU & NYU.

I graduated in the bottom 1/2 of my top 100 school, only took 2 tax courses (Corp & Multinational), and got into Denver & BU (still waiting on NW).

My suggestion to anyone applying is to write a dynamite personal statement (no really they read them and they can make ALL the difference if you're not great on paper otherwise).