Tags to group Team members can be managed at two different levels. On the one hand, in the Teams Admin Center we can set if tags are enabled and from who (Owners, Owners and Members), if Owners can override who can apply tags and if members are allowed to add tags. Additionally, we can add suggested tags:
On the other hand, for a specific Team we can define who can add tags to the Team (By default, Owners are the ones that can add tags).