What enchantments can bows have?
- 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.
Jake King: The bow will wear out, though. According to the wiki, bows have a durability of 385 (= 64·6+1), so Infinity is only as good as carrying 5 more stacks of arrows, and the bow is more likely to not have other beneficial enchantments. And if you are easily gathering the XP to make Infinity bows, you probably can get lots of arrows too.
you have a small chance of getting infinity on a small enchant, so honestly if you get it on a high level enchant you have a great chance of it having flame, power, or even punch to accompany it