It would make me a) a little weary of the gym and b) think about how useful that certification is.
Many gyms(I work at one) are certified spinning centers. If they are, that means the instructor's need to receive their certification through Madd Dog. They teach proper technique and do continuing educatin credits throughout time. One very important thing about this is, learning proper technique!
Too many times have I seen people come in and tell stories of knee injuries because of the spinning instructor teaching a class with unsafe moves, and not suprisingly these classes were taken at non-Spinning certified studios.
I would seriously look into what is tought through this course, what it requires, and if you want to go and teach elsewhere would your certification be worth anything.
Call around to other facilities and see if they even value the program, if they do then it could be worth pursuing, but if it is only valid at your current gym then it is probably not worth your time and money if you can not use it further down the line.