This type of hallway design also appears in the original version of Charlie and the Chocolate Factory (right before the guests enter the room with the edible set pieces).
It would look nice with textures, but it is okay if the whole point is to simply see the effect.
It was purely for the effect. The modelling is ultra simplistic (a cube with a couple of extrusions). However, I may think about producing something more satisfying using the effect.
It shouldn’t matter here, apart from the spheres (added after the effect) it’s a single model. Nevertheless, there’s a definite curvature to the proportional edit (more obvious in side view that the camera view, but you can see it even in camera).