I think the initial discrepancy still stands: Libertarian concept of ownership is not justified. (not according to justice). Economic Inequality can only be maintained using unjustified authority (again justice, not justification!), of course within limits. Libertarians (capital L!) do not strive after a classless society, but Anarchists do.
But quite frankly I don't see any use for either term, with l or L.
I think it's an important distinction; I believe, if a person wants to participate in a hierarchy (and I've met these people who like classes, i.e. the Libertarians), then they should have the freedom to do so. OTOH, people who do not want to participate in hierarchies should also have this right; the world's a big place and I think there's room enough for both of these kinds of people to live, so long as they do so voluntarily. Of course, they would clash if they decided to try to live with one another, but this kind of stuff, the diff between hierarchies and anarchy, seems to be based entirely on a person's personality.
I believe this all falls under the philosophy of libertarianism; I don't think we'll ever be able to convince everyone that anarchy is the answer (I haven't had much luck anyhow), but I do believe we can convince people not to impose their beliefs onto others.