IMO there's a huge difference between being certified and really understanding the products. A certification may certainly help, but I doubt that it will be enough for an employer. What I'd suggest is that - in addition to the online training - you at least build a test environment to become familiar with the everything, i.e. not only the VMware products but also networking, storage, backup, ...
Don't worry, you don't need expensive server hardware to build a lab, you can build a virtual lab on a properly equipped PC. Most of the required software is available for evaluation. For a sample, see Building the Ultimate vSphere Lab
André