Your instructor probably meant that 150 gets you in contention at a lot of law schools, but those are often the ones that are thought to be at the lower end of the rankings.
+1. 150 is typically about the minimum a school with any sort of reputation will consider, albeit they tend to be schools that are very much regional and local in scope.
160+ is where the floor beings for the better schools, and shooting for 170+ is definitely a good goal if you have aspirations toward the Top 14 schools.
Particularly if your undergraduate GPA isn't quite up to par a 170+ is what you should be shooting for any school in the T20, I think.