Is this bulge the result of an asteroidal impact on the other side of Mars?

Hi,

The Martian Tharsis Bulge is not a result of an astroid impact. It's actually a series of volcanoes which are known as the Tharisis Volcanoes. There are 12 volcanoes and the largest known volancano Olympus Mons. What I believe gives the effect of an asteroidal impact is that fact that there is a caldera that has formed within the region. I hope this answer helps you.