Not a bug. Subjugation Wars are supposed to only be available against Indians in your culture group (e.g. Dravidian), but of any religion.
Regular Holy Wars are only available to Hindu, while Buddhist can declare Limited Holy War for a single county. These can only be used against other non-Indian religions (e.g. Sunni or Tengri).
Regular Holy Wars are only available to Hindu, while Buddhist can declare Limited Holy War for a single county. These can only be used against other non-Indian religions (e.g. Sunni or Tengri).