He grew up near Popayán, and moved to Bogotá at the age of 18, where he studied at the National University.
The book examined the negative impact of the local Capuchin mission on native life in Putumayo.
The publication of Bonilla's book led to widespread discussion, reaching the highest levels of government and the Vatican, and eventually leading to the cancellation of the agreement in the 1970s.
The book was later translated into French and English, appearing in a Penguin paperback edition under the Pelican Latin American Library imprint.
Bonilla also exposed the presence of a fugitive Nazi in Leticia in the mid-1960s, with the assistance of Héctor Muñoz, a journalist for El Espectador.