Is he eating regular meals during the day? By the time mine were 8 months, they had 3 meals of baby food. My son ate fruit and cereal for breakfast, one jar each of fruit and vegetable for lunch and dinner. My daughter ate about half that. Plus mid-morning and mid-afternoon snacks (graham crackers, gold fish, cheerios, fruit pieces, carrot dices, cheese, etc. with formula or water to drink). Bottles were just before meals, plus bed time.
If he goes back to sleep on his own at night, it might not be a sleep problem. Maybe it's time you turn off the baby monitor if you have one on him. Children have natural wake patterns through out the night. For mine it's around 11pm or so and again around 3am. Our daughter was never loud enough to wake us up when this happened, so went back to sleep on her own very quietly. (I only know it was happening from when I stayed up late scrapbooking with friends). However, our son was LOUD. He might holler just once or twice, but it would wake up both of us and the dog too. So we turned the monitor off and slept peacefully.
If you really think his problem is hunger though, I'd focus on his day-time meals more so than the evening bottle.