Was he a made guy? Or Harry Maione for that matter? I would assume under Albert Anastasia

Nobody knows for certain. The idea of "made guys" wasn't widely known in the 1930s and 40s so no one asked. My educated guess is that they probably were made guys under Mangano (he was the boss then and Anastasia the underboss).

I think the only murder inc member confirmed to be a made member was Frankie Carbo, who became a Lucchese some time later.

Informer, Joe Valachi saw murder inc as a separate entity or crew of associates, not made members. Valachi co-owned a restaurant with a Mangano soldier and was also buddies with Johnny Roberts. His relationship with Mangano members and street knowledge put him in a unique position to be privy to information. Like faithful suggests it's uncertain, but between the 2 it's possible Capone was made but personally I doubt it.