Is one permitted to study a Hebrew (or Aramaic ) textbook that does not contain Torah in the bathroom if ones primary intention in for the sake of learning Torah?

As long as it is not Torah you can learn it in the Bathroom. Some Rabbis are Machmir that one shouldn't even bring in any Hebrew text in to the bathroom since it is a holy language but Aramaic is not a problem at all. Rabbi Binyamin Bamberger