I am not a Lawyer!

Single member LLC does not require an EIN, unless it is paying payroll or being taxed as an S-Corp.  The single member LLC "disregarded entity" will file a Schedule C.

However, I am not sure if a Partnership can own a single member LLC.  A single member LLC is a "disregarded entity" unless being taxed as an S-Corp.  

I think your partnership owns a multi-member LLC (Partnership).

I am not a Lawyer!

EDIT: Accountant-Man is correct.