Cluster Configuration
This will be Yes if the server is configured as a failover cluster, this does not change based on being  a part of a WSFC or Always On AG.

Source:


  IsClustered:  Server instance is configured in a failover cluster.


1 = Clustered.

0 = Not Clustered.
"
NULL = Input is not valid, an error, or not applicable.

Query to check this:

SELECT SERVERPROPERTY ('IsClustered')