VMware tagging with Ansible

We have a number of VMs we’d like to tag by running Ansible Roles. In order to do this we need to pass the fqdn of the vCenter to the Ansible module, is this easily available as host fact or parameter somehow? We have VMs spread across multiple vCenters so being able to access that information would simplify that process substantially

You should be able to create a GlobalVar and set it in either the host or hostgroup or Location, etc.
Then access it with something like - {{ hostvars[inventory_hostname].vcenter_url }}

The way we do it is use a when: conditional for a .set_fact: block depending on the location, like:

  vcenter_hostname: <apac_vcenter>
  application_tag: <whatever>
  create_date_tag: <today's date>
when: hostvars[inventory_hostname]['foreman']['location'] == 'Singapore'

The difference, though is not just in the vcenter url, but also the tag category IDs.
application_tag: 'urn:vmomi:InventoryServiceCategory:be3f46fd-5bae-4259-bc75-1914abc8a8f1:GLOBAL'
is different than the same tag in NASA
application_tag: 'urn:vmomi:InventoryServiceCategory:3c7c4a12-4287-441e-ad3c-dba8fbxyzefe:GLOBAL'

These tag category IDs get defined in the .set_fact: block.