Gonewest,
If the company stipulates that you wear bars, tie and a hat, then you wear it....
I used to feel a tad foolish getting out of the C207 in the bush with the "full uniform" on. ie I mean the wings, bars (we called them ****-er bars) etc. Fortunately we were north of the 26th parallel (South) so a tie wasn't necessary.
However, getting out of a Dash 8 with the bars, wings, tie and hat didn't feel so bad.
For private flying, I just wore what was comfortable. (Although, I have flown a plane naked. Should I have drawn a tie on?)