if we make transgender bathrooms do we need one for MtoF and one for FtoM?

There's no such thing as transgender. It doesn't matter how much you mutilate your body, how much make-up you wear and how fancy your dresses are, you'll always be a man and people would be able to tell just by your height and skeletal structure alone. Your DNA will always be male. It doesn't matter how you 'identify' subjectively. Your objective identification will always scientifically be male.