I think he is probably interested.
As you have become better friends now, maybe you could give him a hug hello or goodbye, just to test the water a little? See what his reaction is. Have you had any physical contact at all? If you are comfortable with him, and feel like you want to be closer, just be natural with your instincts and show a little more affection.
If it is a real friendship, and nothing more, you wont ruin it by being more open.
good luck