Income equality has a broader meaning than just people doing the same job having similar wages. It most definitely includes the difference between the boss and the workers.
But, if, for each class of worker, there is income equalization, you will find that large companies tend to have an equalizing affect rather than an unequalizing affect. In this example, it's not interesting that bosses get paid more than workers, it is interesting that all bosses tend to get paid the same amount.