What did you do above that with Barn House Burning?
Poems are not lists...but there really isn't a rule about how to do the emphasis here. If you consider the 1-3 format a list, then you would need to restart the emphasis on each line. As I said, I would not. I would consider it text in an alternate format...and treat the emphasis as I would if the whole thing were just a paragraph. Open it before the italics begin and close it where they end.