TransformUtil.cs

using UnityEngine;
using System.Collections;

public class TransformUtil {

    public static Bounds TransformBounds( Transform trans, Bounds localBounds )
    {
        Vector3 center = trans.TransformPoint (localBounds.center);
        Vector3 extents = trans.TransformVector (localBounds.extents);
        return new Bounds (center, extents * 2f);
    }
    public static Bounds InverseTransformBounds( Transform trans, Bounds worldBounds )
    {
        Vector3 center = trans.InverseTransformPoint (worldBounds.center);
        Vector3 extents = trans.InverseTransformVector (worldBounds.extents);
        return new Bounds (center, extents * 2f);
    }
}