A dream feed is done between 10 and 11pm. basically just before you yourself go to bed around this time frame. You just are giving your baby a feed while they are sleeping. With mine this extra feed carried him through so he could sleep instead of waking up hungry and it worked really well. He still woke up to nurse after that but the frequency of his wakings changed. . Your not breast feeding, so you basically just put the bottle into your babies mouth and let them drink. Essentially you are just geting extra food in him while he is sleeping.
Is you baby waking up the same time each night or at random times for food? If it the same time each night he is waking out of habit and that habit needs to be broken, However if it is at different times them he is truly hungry , or is having a growth spurt, and in that case you need to increase his food intake during the day.