when doing a google for "Certified Business Data Modeller" there are about 10 results, 9 of which are selling the course, 1 of which is your post to another forum. That certainly doesn't inspire me with confidence.
CBDM returns about 1,000 (but they look irrelevant)
OCP returns about 286,000 links
MCP about 730,000 etc...
Really it's down to your locality - here in the UK I've never heard of it (but I'm not an employer and I'd never heard of dbforums until I arrived here!).
Why not check your local IT contract/job sites to see if it's being asked for? www.jobserve.com is good for the UK.
On the other hand, whether you carry the qualification on your CV may carry intangible benefits, again I'm not an employer so wouldn't know.