Phone Hom is a company which 50 Blessings, presumably with the consent of the Phone Hom Manager, uses to screen the calls of their 1989 Miami operations. Doing this, they are able to successfully frame the Golden Truckstop as the only traced source of the calls.
After dropping a political job and interrogating Charlie on May 13th, 1989, Biker learns that Phone Hom is screening the calls. He does one more 50 Blessings job before finally investigating Phone Hom's main computer on May 23rd, 1989. He kills the Phone Hom Manager and finds the location of the Janitors before having a showdown with Jacket. Neither win the fight, but both convince themselves they did.
In 1991, the Fans acquire a Phone Hom van from police impound (according to Dennis Wedin), suggesting the police have some amount of knowledge of the illicit activities Phone Hom was involved in. On November 5th, 1991, The Police Chief voices reservations about confirming the source of the calls as the Golden Truckstop, possibly hinting at a knowledge of Phone Hom's involvement, before he's cut off by Jacket's lawyer .