A Canon Lawyer explained that even his direct superior, Father Couture, was not authorized in the neoSSPX order, to expel Fr. Pfieffer.
This act was required by Msgr. Fellay, which he failed to do.
As you can see, the neoSSPX just makes up the rules as they go along.
Fr. Rostand can say anything he wants, such as "Bishop Fellays church".
Besides being a laughing stock, poor Fr. Rostand lacks juridiction and authority to tell Fr. Pheiffer anything.