How was the puppy behaving when Bentley became aggressive/tried to bite?  Was the puppy doing something that might be annoying to an older dog?     
Great advice above.  Also, make sure Bentley has a place to escape the puppy when he wants.  Max always escaped to the couch where Teddy was too small to jump.  Supervise closely.   
I promoted the bond between my boys by doing brief trick training sessions with them.  Tricks for treats.  Having constructive activity helped focus the boys and keep them (Teddy) from wrestling all day.  A little bit of fetch, a couple minutes of shoulder rubs, meal times, a car ride . . . and so on.     
When your puppy is old enough and had the necessary shots, walks together will probably help the most.     
				__________________  Kristin, Max and Teddy          |