From what I've been able to find out, Gilbeys Distillers used to bottle alcoholic and non-alcoholic drinks in Devon Valley, near Stellenbosch. It would appear as though Gilbeys closed its doors some time back and that a couple of its senior executives bought much of the bottling equipment, hand-picked many of the good Gilbeys staff, and started Rostberg Pty(Ltd), a company specialising in the bottling of wine.
Now, this still doesn't explain what the text on this wall is all about - but for some reason I really like the photo. Perhaps it's simply the colouring and incomprehensible black text... I'm not sure.