How to make new Feed Items Inherit a term

Sometimes when adding new Feeds, i would like for each new feed item the feed creates to automatically have a taxonomy term assigned to the feed items.

The case is often in niche sites. Take PSDTUTS for example, a site dedicated to Photoshop. Have a look at the following feed item example:

Array
(
    [title] => Interview with Nelson Balaban
    [description] => At only 19 years of age Nelson Balaban has already done what a lot of designers find extremely difficult to do, set up a good client base and get hired for
commissions. Nelson has a strong hunger ...
    [options] => Array
        (
            [original_author] => Psdtuts+
            [timestamp] => 1244912004
            [original_url] => http://feedproxy.google.com/~r/psdtuts/~3/F5pb5qHsQfs/
            [guid] => http://psd.tutsplus.com/?p=3534
            [domains] => 
            [tags] => Array
                (
                    [0] => Inspiration
                    [1] => Illustration
                )

        )

)

You will notice that the most basic term Photoshop is missing from their tags (makes sense because on their own site all pieces of content would have to be assigned to photoshop, and the tag would essentially be useless).

When i add the new feed, i assign the Photoshop term to the feed, and was hoping that the feed items would inherit this tag but it doesn't seem to. is this a bug or am i doing something incorrectly?