I had been stuck at the fountain with all three companions on three different starts.the fourth time I restarted previous to BoS bunker (make sure you downloaded patches).I went after dog/god first.After retrieving holotape from basemant I saved before approached jail cell with dog in it.I played holotape just as I approached cell,this made dog,god,and the tape on the voice all talk at once.(pissing off GOD).It then came to the way you talked to him in order to get him to accompany you.BUT once he (has to be GOD)agrees to follow you,engage the companion wheel and try to give him a command as in stay,follow,etc. if he obeys then save,and go after the other two...keeping god as your companion (because of the other glitch if you allow dino to be a companion).......hopethis helps because I found it frustrating the first three times through.(XBOX 360 version)......let me know if it has helped