Yeah, All-Star Batman & Robin essentially is Miller's "Robin: Year One" in Miller's Earth-31 Dark Knight Universe.
“Anything I come up with about any of these characters is DKU,” Miller said. “DC winds up adopting just about all of it, anyway.."
In his Dark Knight work, Miller has given readers a glimpse into the twilight years of Batman’s career. In Batman: Year One, he’s shared the beginning of the Batman saga. So where does All-Star Batman fall in his Batman time-table?
“Year Three. Bats is feeling his oats—very young, maybe acting a little crazy, but he knows exactly what he's doing. He's just a bit sloppier about doing it than he's going to eventually get.”