Technically no, it’s not treason, could be if war was ever declared, but it wasn’t. According to the resolution and the war powers act, it’s their option to fund it or not.
But I agree with your sentiment.
What is wrong with demanding some kind of progress over the months? Maybe it will get bush to fire his generals and find a real general grant among them who is serious about victory. I think we need to start being ruthless, we can’t have war without end.