stop the bleeding with a styptic pencil or quiik stop powder. you really cannot bandage an ear. just keep it clean. do not feed him tonite or in the am because your vet will probably have to put him under anesthesia to repair it/sew it up.
The best thing to do is stop the bleeding, ear wounds can bleed like crazy!! Be careful with blood stop powders, they can be useful or harmful. Follow the directions carefully. A lot don't recommened for deep wounds or large gashes. If it is really bad it may not stop on its own, super glue can be applied and works like a charm. suturing can also be affective, but I wouldn't recommend that. I hope everthing turns out all right for you. This is one reason catch dogs have their ears cropped as pups, much less painful then dealing with adult ears. I've heard that shepherds are fence fighters. Maybe some truth to that.