(a) No person shall bottle or pack wine, other than wine bottled or packed in U.S. Customs custody, or remove such wine from the plant where bottled or packed, unless an approved certificate of label approval, TTB Form 5100.31, is issued by the appropriate TTB officer. (b) Any bottler or packer of wine shall be exempt from the requirements of this section if upon application the bottler or packer shows to the satisfaction of the appropriate TTB officer that the wine to be bottled or packed is not