No? Well you should, its not just the Apple watch that this update supports, there are a lot of bug fixes and security fixes included, so I would advise you to update.
Its not just the iOS range that has been updated, the Mac got a security update, as did Windows and Android, or at least if your on Kitkat or above. One of the downsides of Android is that if your not on a recent version you will not get the security updates.
If you can update now.