JOE BAVIER, TANISHA HEIBERG and EMMA RUMNEY FOR South African winemaker Vergenoegd Löw, the pandemic could have been a disaster but a bitter trade war between China and Australia has thrown the 325-year-old estate a lifeline. Bottles of its reds, whites and roses piled up when South Africa banned alcohol sales under a strict lockdown and visitors who once flocked to the vineyard near Cape Town to sip wine and snap photos of its famed Indian Runner ducks vanished. That changed when Beijing slapped tariffs of up to 212% on Australian wine in November after Canberra led calls for an…