Co-op membership is open to individuals only. Companies, organizations, and entities cannot be members of the Subvert Co-op as written in our bylaws.
If you represent a label, you join as the individual who manages it. The same applies to anyone affiliated with a music organization, collective, or other entity.
If your label is run by multiple people, each person can join the co-op individually. When label pages launch, co-managing a label page works the same way as artist pages - you can invite up to 6 people total, and accepting an invite automatically makes them a Label-Member of the co-op. See How do I invite a collaborator to my artist page? for how the invite process works.