[MENTION=8927]HankAAFlyer[/MENTION] put together a pretty comprehensive list of lounges accessible via Priority Pass or AmEx Platinum at Southwest airports, and how easily accessible they are to Southwest passengers in this thread:
http://www.flyertalk.com/forum/south...flying-wn.html (post 9 in the thread has most of it and has recently been updated with 2017 information)
Thank you, thank you, thank you!!