Answer: There is a creative skill and imagination in poetry for sure, but if we're applying labels, I'd put poetry under literature, not art. You might argue literature is a form of art. ... If the answers don't come so easy, then you'll see my point - those are literature, but not art (in my opinion).
I would call poetry an art form because art is a way to express your internal thoughts using external things. You can express your feelings through writing on paper just like how an artist will get a canvas and paint, or how a musician will pick up an instrument and play.