Netanyahu, of course, routinely accuses anyone who disagrees with him of being anti-Semitic. If that were the standard, about half the Jews in Israel would be anti-Semites. The better, and harder, question is whether anyone who rejects Israel’s right to exist is by definition anti-Semitic.
You can only answer that question in the affirmative if you believe that Zionism is an inherent, integral part of being Jewish. Historically speaking, until relatively recent times, that has not been the case. And so, I would say the answer to the question is no.
Personally, I do support Israel’s right to exist, and do not agree with the BDS crowd. In addition, there are certainly plenty of people who reject the whole concept of Israel who are, in fact, anti-Semitic. Being critical of Israel even to the point of refusing to recognize it is not, however, anti-Semitic in and of itself.