In other words, the problem is just looking for the name of the tags (because it's part of the reference to the tag), and not the jcr:title of the tags, which are referenced from the assts. Is that correct?
From a technical point of view this is expected, because JCR imposes some limitations on node names. That means if jcr:title does not match the name, you won't find the asset. Another limitation is also, that if you change the title of a tag but not its name, and you are using this new name to find any asset, you won't get any result.
In both cases it's the problem that the jcr:title of a referenced path is not considered for search, thus more likely a missing feature than a bug.