Are incantations that include devotional words (such as seeking forgiveness and supplications) considered an act of worship for which their doer is rewarded?

Every word a servant utters, be it remembrance of Allah Almighty, praising Him, seeking His forgiveness, or supplicating Him, will be rewarded for it, as long as the intention is to draw closer to Allah the Exalted and Most High. The same applies to what is mentioned in reciting poetry, provided it does not demean the remembrance of Allah Almighty.