No, they are not.
Greeks are not "anti-American", they are however against US foreign policy of handing their homeland over to Islam, as are the Serbs.
Both the Greeks and the Serbs spent 400 years under the Muslim Ottoman Turkish yoke, lost hundreds of thousands of their own fightingin order to finally free themselves from those invaders -- and now we are handing their & their Christian people & land back to Islam chunk at a time, just to buy ourselves some "Islamic goodwill". If it were happening to me, I'd be pissed off at America, too!