It's decent, but sub 12 seconds for the 100m is ideal if you're looking to be an exceptionally good winger at your age. You need to make the most of a minimal amount of space and that's when speed helps. Look at carlin isles... He used to run track but now is in the American sevens team after only a few months of playing rugby. He isn't exactly the finished article yet, but that's just an example of how speed can help you play rugby

Track times have little to do with how good a player you'll be.