Working for modest benefits can take years of meetings, reports and negotiations. And nearly every employee group and corporation must go through the same long process. It was once thought that registrations would encourage private businesses to offer benefits. It does not, however, appear to have been the instigating agent. There are hundreds of laws that reference the status of legal marriage.
Registrations trigger very few benefits, if any, in the ordinances of the issuing jurisdiction.
Outside of that jurisdiction, they are entirely worthless. The most a registration generally does is to allow you access if your partner is in prison or in a hospital. Usually they don't even allow you to make medical decisions, should your partner be incapacitated. To find out if there are any benefits whatever, you need to contact the issuing license department and inquire. It is possible that a registration could be used against you to take away government subsidies or benefits, should an agency claim the registration makes you responsible for your partner's welfare.