git-annex setup with bare remote and optionally bup?

[Richard Hartmann]

Also, bare git annex repos only know about themselves and not other
repos. Again, this is somewhat expected, but still.

The more I think about it, the more do I think that a combination of
object stores of bare & non-bare repos makes sense. Only need to
figure out the cleanest way to meld bup into that.

@joeyh: Is there anything which makes the combined object store a bad
idea? Could/should the code know & expect such a use case?