How to warp/bend a multilayered object?

I want to add some waviness to a snake plant leaf. I know a few ways to bend shapes (anchor point tool, curvature tool, warp, distort and transform). But when I use any of these methods, the warp effects all of the objects that compose the leaf, creating an unwanted effect. The first image shows the leaf pre-warp and the leaf post-warp.  How to I get illustrator to see all of the layers as one object, so I can add a more natural looking waviness to the leaves (shown in second image, which is an example I found online)?