Currently "sponsored" tags are only available for tags in which a sponsor has ponied up cash for.
Since most open source communities cannot afford or justify the expense of purchasing a "sponsored" tag, I propose that each eligible open source community should receive a free sponsored tag among those relating to their project.
Eligible projects would include, but not be limited to Python, PHP, Java, HTML5, Drupal, etc….
I asked a question on M.SO regarding the use of Java's BSD licensed Duke mascot since Java is curated by the OpenJDK project and was pointed here to sort out the general case.
I do realize some projects do have corporate sponsors behind them, such as Oracle to Java; however I believe these types of projects have more community momentum and would continue even without the corporate backer. Other projects depend on the corporate backer for momentum, such as IIS, Oracle DB, etc.
However I contest it's very commonplace for products sold by companies to be given gratis to open source communities and projects, as a way of giving back to the FLOSS communities (as it's challenging to find any software that is not based on or influenced by the hard work of the FLOSS movement). I see no difference here -- if Microsoft wants to "sponsor" the IE tag, they can since it's a proprietary for-profit product. But if Apache wants to sponsor the httpd tag, they should receive it gratis since its a free open source project anyone may use.