The useful question is not whether a material is certified. It is what the certificate covers, and — more importantly — what it explicitly does not.
Chain-of-custody standards such as GRS and RCS verify provenance. They say nothing about abrasion resistance, colourfastness or batch consistency. OEKO-TEX STANDARD 100 tests for harmful substances and says nothing about sustainability at all; a fully fossil-based virgin sheet can hold a valid certificate.
Record every certificate alongside its scope and its exclusions. The exclusions column is where your risk lives.
