"[Y]ou have not shown that the individuals who participate in the CLEA LTD program are all employees of one such employer, i.e., the State of California. Instead, you suggest that the CLEA LTD program participants have a similar commonality to that shared by federal employees because they are covered by a state-mandated benefit package and participate in the CLEA program as a supplement to that state-mandated benefit package. However, even if state law entitles a diverse group of employees to specified benefits, that fact alone would be insufficient to satisfy the commonality requirement.... We do not view this commonality requirement as satisfied where the association's membership extends to individuals belonging to a variety of associations, unions or clubs."