Great question but not a great answer is available. If the "bale" was compressed into a solid cube, it was peat. If the material was in a typical bag such as potting soil, and was loose and fluffy, it was sphagnum. The source is no help since both sphagnum and peat come from Canada. You'll also see it from Peru and New Zealand/Australia. I have never seen sphagnum from Europe, though Scotland and Ireland produces tons of the stuff.
It seems that every big-box store carries those peat bales but few seem to have milled sphagnum. The only producer of milled sphagnum that I know of is Miracle-Gro. Miracle-Gro used to supply it in 3 cf bags but now it comes in 2 cf bags and there is slow-release fertilizer added to this new material. Before, the milled sphagnum made a great starter (non-soil) material for seeds and for rooting, but now with the fertilizer added, I don't know if it still would be good for those purposes.
The baled peat should be great for your blue-berries. The easiest way to use it is to soak it in water. It will expand and become workable.
