How much ply is Alpaca sport weight wool?

The number of plies is independent of the weight or fiber content of the yarn. It is possible to have a single ply super bulky like Brown Sheep's Burly Spun, or something like the 8 ply fingering weight on my sock needles right now.

If you want to know the plies in a specific yarn, we'd need to know the brand name and yarn name.