Tags are used by some search engines but not others. In particular, Google doesn't bother looking at the tags. Having said that, tags are still useful as internal indexing (e.g. I believe they play a role in displaying 'related hubs' - which can generate you traffic that way e.g. when a reader is on a related hub and then clicks on yours from there). Also you can use tags to help generate RSS feeds between your inter-related articles - but the tags don't need to be long for this.
So don't get overly hung up on tags - just use ones that reflect what you are writing about - this may include the title of the hub topic, but not if it's too long.
So my conclusion is the same as Rock_nj and learner365 which is that if it constitutes too long of a phrase (more than a few words) it could be a problem. Otherwise sure, why not?