with regards to
I have checked patch on MOS. It is available for EBS 12.1 and there is no superseded info available in patch search which means that patch is not superseded. If it would be then in patch search window you would see that and link to new patch.
Not sure how relevant it is but please check:
What is the Latest E-Business Tax (eBTax) Rule Engine Patch? (Doc ID 1301356.1)