The problem with spray bottles is largely determined by what you plan to put in them. Oftentimes, it is some sort of cleaning product or other toxic bastard chemical. If a cleaning product, if home-made, you can expect to find some chemicals that like to eat away at the PS parts that usually make up the spray mechanisms in these bottles--the seals, gaskets, the interior bits of the spray nozzle.
The bottle is usually fine because they are made of PP, but it's the little bits you never see that are quickly eaten away be ethanol or other harsh, highly-concentrated alcohols that you might be using. *i think* Isopropanol is usually fine, and probably what you are more likely to find in typical cleaning agents; but in the lab we tend to use 70% EtOH for general cleaning/sterilizing of surfaces. You have to use those simple squeeze bottles with a nozzle, because they are basically one or two whole pieces of PP, and no PS junk that quickly deteriorates. That stuff will break a typical spray bottle within a week or so.