In the previously linked interview with Enrique Vila-Matas, his answer to the last question, quoted below, reminds me of another mention of Bolaño as a "brother".
Vila-Matas: Meeting Bolaño in 1996 meant that I no longer felt alone as a writer. In that Spain, which was trapped in a provincialism and an antiquated realism, finding myself with someone who from the very first moment felt like a literary brother helped me to feel free and not consider myself as strange as some of my colleagues would have me believe. Or maybe it was the opposite: I was stranger still. We laughed together very much. We wrote letters to imbeciles and we talked of a beauty that was short-lived and whose end would be disastrous.
Here's Chilean writer Alejandro Zambra, author of Bonsai and The Private Lives of Trees, in an interview in June last year:
Q: What do you think of the Roberto Bolaño phenomenon in the US?
Zambra: I think what has happened with Bolaño is wonderful. His work deserves all the attention in the world and it’s impossible to exhaust it in one or two readings. On the contrary, we will be reading and re-reading his books for a long time to come. Bolaño is to me like an older brother whom I admire without reservations. I anxiously await his return from his travels so I can listen to his stories. I don’t want him ever to die. And don’t tell me he’s dead. I won’t believe you.