Northwest: It's Air New Zealand's fault

UPDATE: I got the official response from Northwest

......
You should understand that Northwest Airlines offers the same employee benefits and travel privileges to its employees' domestic partners as it does to employees' spouses, including benefits and privileges that extend to domestic partners' children. Northwest does not discriminate against domestic partners and is fully compliant with California's employee discrimination laws.
......Northwest's policy is to only offer travel privileges to other airline employees to the same extent that the other airline offers travel privileges to Northwest employees.
......
In August 2000, Northwest sent Air New Zealand a letter requesting them to sign the new interline agreement. Air New Zealand never responded to Northwest's letter,
......
The airline employee involved in the ACLU's press release, a Mr. Robert Anders, is an employee of Air New Zealand. He apparently won an interline pass from Northwest Airlines as a prize at an Air New Zealand holiday party.
......
Consequently, Northwest has decided to permit Mr. Anders and his domestic partner to use the pass. We apologize to him and his partner and we hope they will understand how and why the incident arose.
......

From Advocate

A representative from Northwest Airlines told Anders that the airline would recognize only a spouse, another airline employee, or a dependent child as a companion. The representative specifically stated Northwest Airlines would not recognize a registered domestic partner as a spouse for the purpose of the tickets.
In its letter to Northwest, the ACLU said that the Unruh Civil Rights Act, part of California law, "mandates 'full and equal accommodations, advantages, facilities, privileges, or services in all business establishments of every kind whatsoever' without regard to sexual orientation or marital status." "Because same-sex couples who wish to marry cannot currently do so under California law, using marriage as a criterion discriminates on the basis of sexual orientation," Sun said. "Northwest's policy also discriminates on the basis of marital status because it does not permit unmarried heterosexual individuals to bring the companion of their choice."

Let's see how Northwest deals with this. It looks like a law suit now.