(Reuters) - A new class of wine makers is emerging in South Africa with blacks, many of whom once worked the land, now taking over vineyards in an industry dominated for centuries by whites. There are only a handful of black-owned vineyards in the $3 billion a year industry but the number is expected to increase as the government tries to unwind policies under colonial rule and then apartheid that forced blacks off the land or into slave-like work at farms.