Four short lines, and a whole mood of giving in. The speaker has been "taken" by a night bus, as if the bus made the decision, and yet they say they're glad. There's relief in being carried along, in not having to steer. Night travel often feels like that: you're between places, nobody expects anything of you, and the dark outside the window makes everything seem suspended.
The second stanza turns strange and funny. Growing fur suggests slipping out of the human world and becoming something simpler, more animal. Believing "in the god of debt" is darker. It hints at the pressure of money and obligation, the thing that might keep people riding buses at night, and the speaker seems to accept it with a shrug. The tone is deadpan, half joking, half resigned. The poem leaves us with an odd contentment: giving up control feels like freedom, even if what you give it up to isn't kind.