it has been a long time since i read the book so forgive me if memory is hazy. but i believe roemers book depicts a mostly fictitious 'war' between the outfit and the bonanno family in the time period after anthony spilotros murder. it puts blame on outfit for taking out spilotro no surprise in that but it gives impression that post 1986 the vegas rackets were then up for grabs and that the bonanno family made a push to take them over. more specific though is that it was joe bonannos west coast crew specifically who made a grab at them. i dont think this scenario ever took place re outfit vs. bonanno family in a straight up war similar to that described by ny mafia above regarding cleveland and pittsburgh crime families.
there was definitely an outfit presence in las vegas after murder of spilotro bros in 1986. their must have been money still on street from loan sharking that needed to be collected and other rackets which jives with some indictments that came later in late 80s and early 90s. but again i have never seen anything conclusive about a war. further to that if any war did happen we hear nothing about it when ; joe massino begins to cooperate a guy who was near the top in bonannos around this time. or sal vitale for that matter or any of the other high level made men in the bonannos that cooperated that may have had knowledge of said conflict between 2 families.
so then who did joe bonanno still have with any power and influence around him to make a putsch against of all families the outfit in the 80s and the answer is no one because nothing ever happened.