There are specific techniques for breathing and I see pretty much every pro employ the type of control that can help you ride more efficiently. It takes some getting used to but when you look at swimmers, you must agree that breathing while swimming fast is a learned skill.
As with your legs, cadence, muscular endurance, sprinting, bike handling, climbing and breathing-- controllable physical activity can be trained to be more efficient.
There actually is alot written about it and since breathing is basically fuel for your blood, the most efficient way to do it will definitely improve your speed. It feels very unnatural at first but do you remember the first time you tried to swim and breath?