As was said earlier: he cut a deal with the Commission to step down as head of his family and "retire" to Tucson in return for not being whacked. Not much of a concession on his part because very few members of his family were still loyal to him by that time.

"A Man of Honor" is a pretty good read. Of course Bonanno never admits to any crime--even jaywalking--after Prohibition (it's an autobiography, after all). But, his co-author (Bonanno's English was limited) is an elegant writer, and there are plenty of good stories in it. An irony: Bonanno provides the only extant description of the Commission's operations. When Rudy Giuliani was the US Attorney for the Southern District of NY, he read "A Man of Honor" and saw in Bonanno's description a perfect example of a "Racketeer Influenced Corrupt Organization" as defined in the RICO law. That lead to the Commission Case and the wholesale prosecution of Mob bosses all around the country.