Fine chippings are fine as bedding ONCE THEY ARE DRY. But depending on what the tree company was running through their shredder, they can be quite green and moist when you get them, in which case it is important to dry them out first because they can mold something FIERCE, and real real quickly too.
Coarse chippings, more like mulch, won't do too much good as bedding (better than *nothing*, but not that much better) and would be best as run footing (for a very dry and well-drained run) or used in the garden as mulch or composted for soil amendment.
Good luck, have fun,
Pat