I rarely use PVC/RNC, and dare I say don't often use bushings on it either, because often the only times I use it, it will have Bell End, and a steel conduit on the other. But yep, required.
352.46 Bushings.
Where a conduit enters a box, fitting, or other enclosure, a bushing or adapter shall be provided to protect the wire from abrasion unless the box, fitting, or enclosure design provides equivalent protection.
