In Sizwe Bansi Is Dead, what does the term "ciskeians" mean?

In Athol Fugard's play Sizwe Bansi Is Dead, a man who says his name is Robert Zwelinzima but who is actually Sizwe Bansi ("sizwe" means "the nation" or "the county," and "bansi" means "large" or "broad"), comes into the photography shop of a man named Styles. Zwelinzima says the he wants to have a photograph taken of himself so he can send it to his wife, who lives in a territory of South Africa called Ciskei.
Ciskei was a bantustan ("bantu" meaning "people" in the Bantu language, and "-stan" meaning "land"), a supposedly independent and self-governing territory set aside for black inhabitants of South Africa. Ten bantustans were created in South Africa under apartheid as a means of separating black people from the white South African population.
"Ciskeians" refers to the residents of Ciskei and to residents of bantustans in general. "Ciskeian" is a derogatory term for the so-called "independence" of black people living in South African bantustans.

BUNTU: [To the audience]. Back there in the Shebeen a Member of the Advisory Board hears that he comes from King William’s Town. He goes up to Sizwe, "Tell me, Mr Bansi, what do you think of Ciskeian Independence?"
MAN: [interrupting]. Ja, I remember that one. Bloody Mister Member of the Advisory Board. Talking about Ciskeian Independence! [To the audience.] I must tell you, friend . . . when a car passes or the wind blows up the dust, Ciskeian Independence makes you cough. I’m telling you, friend . . . put a man in a pondok [a crude, barely livable hut or shanty] and call that independence?