Staff of these companies are allowed to register for free bus travel for three dependents, such as for spouses, parents or children.

New World First Bus Company Staff Union said on Facebook on Sunday that the policy would cover spouses as long as they held a valid certificate of marriage.

The offer would not be subject to the dependents' gender.

As for child dependents, the offer applies to them as long as staff can present relevant proof," the union said.

"We are delighted to see the company's progress in policies and its open-minded gesture. We also hope to see continuous improvements and progress in other policies by the company."

KMB similarly said spouses are entitled to free bus travel as long as staff can present a certificate of marriage.

"The offer has nothing to do with the gender of staff and their spouses," it said.

According to KMB's policy, its staff can register for free bus travel on behalf of two dependents.

After working in the company for a decade, they can register three more dependents.