Green’s Dictionary of Slang

(US prison) excellent, first-rate.

1926		Times Despatch (Richmond, VA) 17 Oct. 7/7: Bonnie Rue – Anything that is a better than the ordinary, like a Bonnie Rue job, or Bonnie Rue food .
1933		J. Spenser Limey 269: I think the word ‘boneroo’ has a Mexican origin. At San Quentin it means, among many other things, ‘privileged.’ ‘A boneroo guy’ is a man with enough influence and money to wear boneroo clothes and have a boneroo job and mix with a boneroo bunch. [...] 274: I used to spend hours chatting with another ‘boneroo’ guy.
1935		D. Lamson We Who Are About to Die 108: Altogether it [i.e. a prison job] is very bonny-roo, or would be if it weren’t in the Hole.
1936		San Quentin Bulletin in L.A. Times 6 May 7: BONARUE, good, excellent.
1940		L.L. Stanley Men at Their Worst 212: To send Keyes in ‘jute’ meant murder. Therefore he was given a ‘bonarue’ job on the Porch, handling packages.
a.1949		N. Algren Little Lester’ in Entrapment (2009) 94: A veteran conaroo who called himself Bonarue Katz.
1960		(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 14: Bonaroo – the very best; Bonnie Rue.
1967		M. Braly On the Yard (2002) 142: These are boneroo free-world shoes.
1973		Maurer & Vogel Narcotics and Narcotic Addiction in Maurer Lang. Und. (1981) 284/2: bonaroo 1. Good narcotics, uncut or cut only a little.
1975		J. Carr Bad (1995) 58: The sandwich man [...] had bonneroo rolls and cookies.
1977		E. Bunker Animal Factory 50: Did him a few favors, bonaroo clothes, et cetera, before Ron knew the score.
1986		J. Ellroy Silent Terror 66: ‘You talk about bonaroo pussy, man’ .
1999		E. Bunker Mr Blue 367: A convict was assigned as a ‘fire watch’. It was known as a bonaroo job. Whoever had it, had the run of the huge old building.
2001		(con. 1964–8) J. Ellroy Cold Six Thousand 172: White horse — all plastic-wrapped — three bonaroo bricks.
2021		J. Ellroy Widespread Panic 7: I’m beefcake, boss, and bangin’ them bonaroo bitches.