Is it a sound idea to do view frustrum culling for all 6 faces of a point light? For example, my RenderablePointLight has a collection of meshes for each face.
Is this about a shadow-casting point light which renders a shadow map for each face?
If your culling code has to walk the entire scene, or a hierarchic acceleration structure (such as quadtree or octree) it will likely be faster to do one spherical culling query to first get all the objects associated with any face of the point light, then test those against the individual face frustums. Profiling will reveal if that's the case.
If it's not a shadow-casting light, you shouldn't need to bother with faces, but just do a single spherical culling query to find the lit objects.
Yeah its for shadowmapping. How do you do a spherical culling query?