Re: What is this? Cluster feeding or no milk?
My second baby was sort of like that. I would put her to bed, and 5-60 minutes later she would be up again, wanting to nurse. And then 5-60 minutes after that, for the first 2-3 hours of the night. It wasn't lack of milk- I had a whopping oversupply- it was simply that her first stretch of sleep was very, very light and she would wake frequently and need assistance in getting back to sleep. And nothing gets a baby back to sleep better than nursing!
Now, if I had given my LO a bottle I have no doubt she would have taken in, and probably drunk a large amount. Babies almost always drink a lot from the bottle because the bottle delivers a rapid milk flow regardless of whether the baby is sucking lightly for comfort or eagerly for nutrition.
If your LO is satisfied at the breast at all other times of day, don't worry about your supply. This is probably just a need for mama to help him with sleep.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"