To be completely honest, a bachelor of commerce is not really useful (unless you are majoring in accounting or finance).
Managing people and marketing is more of a talent, rather than something you can learn (although practice can make you better, you still cannot beat talent). So in essence, a commerce degree is just to make you appear more employable in those areas. If you however want to do accounting/finance, then yes a commerce degree is highly beneficial.
On the other hand, if you want to do something like science or engineering, then yes, uni does matter.