Big box store treated lumber will plane fine. (Its about all ACQ now). As with any pine, you may have to clean the rollers more frequently. I have done it numerous times. Let the wood thoroughly dry first (a week or two minimum with the boards on end/edge or stickered to provide air flow on all sides). When wet or damp, the wood tears instead of cuts, and the fibers make a mess of your equipment as well as the surface will have tear-outs.
Creosote treated boards are different, and I would be leery of the health issues as well as destroying the rubber on the rollers. Can be really tough on blades, also.