Not in the workplace, but I used to work in school where one of the boys was constantly at loggerheads with some of the others. Basically, his family were Brahmins, quite a high caste, and he would often refuse to work with children of lower castes. The school (and, indeed, British law, as far as I know) did not recognise the caste system and therefore would nip his attitude in the bud PDQ.
Sadly, many Hindu families do still operate the system here two and three generations after leaving India. Luckily there are many more (where I live and work, at least) who recognise it for the barrier to society it is.
Sikhs, of course, do not recognise the system at all. If any are practising anything like it, then they're not true Sikhs.