If people are ignored because of their inability to speak standard English, what have they encountered? would they be language bias, language variety, language prejustice or language snobbery

This should be language snobbery

Language prejudice does not necessarily mean you would ignore someone, just have prejudice about their language. Variety is not a bad thing and bias is not so harsh.

The correct answer is language snobbery.

Linguistic snobs are those people who refuse to talk to others who are not using standard English. So, if a person is using a non-standard dialect of English, a linguistic snob might choose to completely ignore them because of their substandard dialect. These people believe that only their dialect of that particular language is correct and refuse to listen to others.