Most would remember their breeder, but that would depend on how much inter-action they had with him/her during the time they were still there. One of mine, who I kept back with his sister (who we were keeping) for a friend, to allow him to grow on a bit before joining her small pack, definitely knew us when we later met up at a show. In fact, for a scent hound, remarkably he saw us coming from quite a distance (and any wind was coming from him to us). His tail started a slow wag which increased the closer we got.
Litter mates is different I suggest as dogs go by scent usually and once away from the others, each just become ‘another dog’. There will be familial traits that may be recognised however.