Technically, linux-distribution is a broader tag than gnu-linux-distribution, since the latter includes distributions that include Linux but not any GNU software (that's common in small embedded systems, for example I don't think that my router's operating system includes any GNU software).
However I don't think there's much of a need to distiguish tags with this level of detail.
When it comes to naming, tags should have names that are easily recognizable and discoverable by users of the site. Tag names should be chosen to be easy to find and to understand; political correctness doesn't enter into it. Wikipedia is useful to settle on terminology because it's both a reference that people can consult if they don't know the meaning of a term, and a reference that people can consult when they're looking for a standard name for a concept. On Wikipedia, the article “GNU/Linux distribution” redirects to “Linux distribution”. The Talk page contains as would be expected a debate about the use of the term “GNU/Linux distribution”, but even there there was no proposal to make “GNU/Linux distribution” the title of the article.
Regardless of where your personal sympathies go, what matters is language as it is. The term “Linux distribution” is in widespread use, “GNU/Linux distribution” is not. Inventions are often not named after their inventor; even if Linux had started off as a GNU distribution (it didn't!), that doesn't imply that a Linux distribution must be called a GNU distribution. So the tag name should be linux-distribution.
Besides, gnu-x11-apache-linux-tex-perl-python-freeciv is too long for a tag name.