Yes there certainly is a Tai Chi certification.
The Tai Chi Certification from American Tai Chi and Qigong Association independently accredits Tai Chi teachers, schools and practitioners of any style, program, lineage or application. Bear in mind you need to complete over 100 documented hours of formal instruction and it does not automatically qualify you for the ATCQA Certification. The decision will also depend on the credential of the organization(s) from which you received Tai Chi training.
Find more information on the ATCQA site