As of 1.1 bows can be enchanted, what enchantments can they be given and what approximate level are they?
- Power - Extra damage (Up to Level 5)
- Punch - Knockback effect (Up to Level 2)
- Infinity - As long as there is one arrow in your inventory, you will have infinite arrows.
- Flame - Sets arrows and mobs on fire.
- Unbreaking - Extra Durability (Up to Level 3)
- Mending - Increases the item's durability as you gain XP (only costs XP to enchant initially)
Taken from the Minecraft Wiki.