In Spain, we usually stay with relatives and take gifts for them; but 'hostal hosts?' No!
When we stay at hostals, we are paying guests and the hostal owners or managers are 'for profit' entities renting us accomodations as long as we pay for them.

I, for one, don't think it is necessary or appropriate to consider oneself obligated to bring a gift for what you call your 'hostal hosts.'