Are SURF descriptors normalized with respect to orientation?
The SURF descriptor implicitly accounts for orientation of the interest points based on the distribution of edge intensities around it. So yes it is invariant to rotation. This is also mentioned in the description of the SURFPoints class:


  Orientation   
  
  Describes the orientation of the detected feature. This value must be
  specified as an angle, in radians. The angle is measured from the
  X-axis with the origin at the point given by the Location property.
  Typically, this value gets set during the descriptor extraction
  process. The extractFeatures function modifies the default value of 0.
  Do not set this property manually. Rely instead on the call to
  extractFeatures to fill in this value. The Orientation is mainly
  useful for visualization purposes.
  
  Default: 0.0