I took the 135 test, because I flew (and fly) 135. I can't remember if there was any indication on the test results or not. There is certianly no indication of it on the certificate.
IMHO--Take the test with the flying you intend to be doing in mind. If you should change later, it shouldn't be a problem. You will be looking at regs at regular intervals anyway, whether they turn out to be 121 or 135.