Partition external drive to work on wbfs and pc or mac?

Is it possible to partition an external hard drive and use it for both wbfs (wii backups) and a mac? i have a western digital my book essential of 230 gb and i would like to partition it to 130gb for the WII backups and 100gb for a mac. if i format it on a pc and then partition it will a mac still read the portion thats readable for the PC? im asking that because i have a PC and a the person who owns the WD has a MAC. answers and suggestions would be greatly appreciated, thanks.