I need to document the relationship between two religious
organizations: that of Cheri Huber, (cherihuber.com &
thezencenter.org) to San Francisco Zen Center. I am hoping to find an
objective source that shows the "X degrees of separation" between them
-- a directory perhaps. Usually Buddhist teachers use the lineage
(e.g., X's teacher was Y; Y's teacher was Z; all the way back to the
Buddha), but Cheri, as a principle of her teaching, refuses to say
anything about her origins. I wonder if she and her organization are
members of any larger group of Buddhist teachers, or women Buddhist
teachers, or something like that.

I don't think you'll find a relationship between the San Francisco Zen
Center and Cheri Huber.  Similar to Charlotte Joko Beck, Cheri Huber
appears to be a teacher who does not focus on lineages as a means to
validate her teachings.

It's true that, exactly like Beck, Huber does not rely on lineage.
However, for Beck it IS possible to learn about her history, and use
those prior experiences to explain how she got to the position she has
taken. I have not been able to do so with Huber. Where does she come
from? Where did she study? These things are part of the reality of any
teacher, and I have a problem with this being kept so mysterious. I
have need the information ot help one of her disciples, so I'm sad she
and her helpers won't give it. Oh well.

In the spirit of Zen, you might want to consider why it is so
important to know who her teacher is.  What does it give to you or me
or anyone to know who a teacher's teacher is?  Or a teacher's history?
 Is there a belief at work that imbues some importance to the lineage?
 And suppose you did know her teacher's name - what then would you
want to know?  Perhaps who her teacher's teacher was, what the lineage
of that relationship was?  I wonder if it's possible to accept the
teachings, rather than the teacher, as the instrument of awakening. 
We (me included) imbue our teachers with a lot; it's worth considering
what those projections are and why they have meaning for us, to my
mind.

In the spirit of Zen, you might want to consider why it is so
important to know who her teacher is.  What does it give to you or me
or anyone to know who a teacher's teacher is?  Or a teacher's history?
Is there a belief at work that imbues some importance to the lineage?

DW:  Yes: I am a lawyer, and I have to file papers with the US
government which include that information. The belief at work is that
I must comply with the lw or my client -- Cheri's student -- will be
out of luck.

And suppose you did know her teacher's name - what then would you
want to know?  Perhaps who her teacher's teacher was, what the lineage
of that relationship was?  
DW:  Yes, I'd want that too. 

I wonder if it's possible to accept the teachings, rather than the
teacher, as the instrument of awakening.

DW:   I'd be happy to accept the teachings, but the US government does
not agree to accept the spirit of Zen as a proper legal definition.
They require me to explain how her organization is related to other
organizations.

Apologies for the duplications in the last responses.  Don't know what caused it...

So it's not a Zen issue, but something else, it seems, that might be
better served by going directly to the source (why the US government
cares about her lineage is obvioulsy relevant to the case you are
filing).  If your client is a student of Cheri's, it might be best to
contact her directly (if that hasn't already been tried).  I really
don't know who her teacher was, having been given the same answer you
seem to have gotten.