I know we all love to go out love all our horse's, but if your talking about real bonding, that comes when the horse relinquishing his leadership to you. True bonding happens when the horse knows he can trust you to keep him safe.
Bonding 101 at our house?
Tarp training, put some hay in the middle of a big tarp and encourage him to eat off it.
Set up a little trail course and hand walk you horse thru it. Backing them through a "L" takes trust on their part.
Practice an emergency get out of the barn with a towel over his head. This must be done very very slowly. I started by just covering their eyes with my hand for longer and longer.
Got a kidde pool? Throw some grain in the middle and let him try to eat out of it.
Bonding comes from working with the horse, he develops more and more trust in you and accepts that when you ask him to do something it's okay he's not going to get hurt.
You can feed him trreats all day, that's not bonding, your just a Pez dispenser.