No. Winterboard has been around a long time. Devs have created thousands of themes and tweaks. Many have nothing to do with the iOS version install and should work with any version. Many have been updated (where necessary) for compatibility. But you will always find old ones ... and that's ok Some users are still on old iOS versions, including 1.1.4 and 2.1.4. 2G users have no choice as they are limited to iOS 3.1.3 and 3G users are limited to iOS 4.2.1.
Some Winterboard themes and tweaks are compatible with everything.
Some Winterboard themes and tweaks are only compatible with 4+ iOS.
Some Winterboard themes and tweaks are only compatible with 3+ iOS.
Some Winterboard themes and tweaks are only compatible with < 3.x iOS.
I have never seen a 'list' which details which Winterboard themes and tweaks are compatible with which iOS version. I don't think anyone knows this answer
The best answer is to download the themes and/or tweak and try it out. If it works you're good. If not, try another or beg for an update from the theme/tweak author
Side note: My 2.x memory is a bit rusty. Not sure when Winterboard was first released (haha). I think back in the 2.x days