1995 Pontiac Grand Am brakes

I did a front brakes serivce, changed pads, and rotors, also rubber lines because they were old.

when I bled the the front brakes, everythign was fine, but the rear are not even getting pressure, do not work, I bled the master cylinder where there are two bleders and in works fine, I never got this kind or problem before and I want to know why the rear brakes do not get pressure and do not stop the wheels.

I know theres is an ABS light, the book says to star t the car and not to press the brake pedal if the light does not go away agfter 3 second and stays more than 8, I need to know what I have to do next, I know I still have to check the rear brakes shoes, but I know there is a good pedal, it is not spongy and it does stop the front wheels, please write me back, also it has a good brake pedal.

Thanks.