It really depends on what your focus is or where you feel new opportunities would lie. Technically, the two certifications do not depend on each other and can be taken in any order.
If you plan to work on Enterprise
Java, then SCBCD is a logical progression from SCWCD. SCMAD does not depend on any knowledge gained from SCBCD. However, if you are interested in working with mobile applications, it is the right one to take.