As of late I've just been using the regular Wal-Mart brand of half and half 2 Tbsp. is 1 point. So if I'm using 2 servings it would be 2 points. But I prefer to use the Land o Lakes fat free, and you are correct in saying that it is zero points unless you use more than one serving, then i'd count it as one.
I'd eyeball a tbsp. and overcompensate by a point just in case.