I don't know if my therapist has gone/goes to therapy herself, but I hope she has. I personally believe all people, even those who do not have mental illnesses, can benefit from therapy. That said, it's the same for therapists as it is for us -- they only get out of therapy what they put into it. If they "phone it in" because it's a requirement for their degree, or whatever, they probably didn't benefit much.
My T seems to be really self-aware when she says things that don't make me feel better (such as "I don't have a solution to this particular problem -- I know it sucks to hear that, and I'm sorry), so I wonder if she has gone to therapy and recognizes what is and isn't helpful. Then again, she could just be naturally self-aware.