If you read the boards from most of the professional organizations (like ACCP, etc.), you would find most of the opinion about the BCMAS is negative.
Name one company that has required the BCMAS as a credential for hire? The organization behind the certification, ACMA, is a profit-making institution and has no recognition by any professional organization like ACCP, ASHP or AMA.
Most of the input from individuals has been highly skeptical. Until some large, influential player in industry absolutely requires a BCMAS as a valid credential for hire/promotion/tenure decisions, it appears to be yet another money making scheme to wrestle money from those practicing clinicians seeking to get into industry.
I manage the medical affairs division for a pharma company, and right now, we're not buying it--at all.