No. Ply: two or more yarns that have been twisted together. The yarn count per inch would make a denser or heaver material but bunting is supposed to be lightweight for flyability, a loose weave. Wrap & Weft, are deferent and a method most likely not done on CW period bunting material. The number of twist adds strength as did mercerizing cotton yarn. A more modern way to explain ply, ply-yarn such as automobile tire yarn, may have 9, 10, 11, etc., ply.

Some refer to ply as a number of finished material sewn together, which is not so.

Happy Trails!
Tom Martin