MCB major + Mathematics Minor?

I’m currently a second year at UCB planning to major in Molecular and Cell Biology with a focus on developmental genetics. I would like to pursue a graduate education, however, in either computational biology or bioengineering. Would minoring in math increase my chances and preparedness for admission into either of these programs at premier universities?

for computational biology CS would help you more than math. For BioE, not really. You can do BioE minor:
http://bioeng.berkeley.edu/undergrad/bioeminor