Wearing epaullettes is a no no for a PPL in my opinion. The rule I abide by is if they form part of a uniform, you wear them. PPL's don't have uniforms. End of.
In as far as walking around town wearing them, well that's another story. That says more about the person wearing them than anything. The first thing I do when I finish a duty and my pax are away is put them in my top pocket.