I've run into a similar problem trying to create a wooden arch constructed from straight segments of wood. Originally, the procedural texture just maps across all of the segments uniformly, i.e. the wood grain ignores the orientation of the segments.
My workaround has been to switch to a dummy texture, then rotate rotate the segments so that they align with the procedural grain. Apply the rotation, then reapply the procedural texture, and rotate back into place.