I was happy to find many gluten free options in Cape Town. First of all, all packaged goods are labeled with whether they contain gluten or not (and even labeled if they have genetically modified ingredients!). This was a relief coming from the U.S. where our food labeling leaves something to be desired.
In terms of restaurants, we ate at:
Fork (city bowl), which had a complete GF menu of AMAZING tapas
Quay 4 (waterfront), which was incredibly knowledable about GF issues and was a wonderful place to get seafood
Harrie's Pancakes (waterfront) Pancakes mean crepes and they offer GF crepes
Crepes by Suzette (de waterkant), another crepe place with GF crepes
Adis in Cape (city bowl) an Ethiopian restaurant, which serves NOTHING with gluten in it. Amazing food.
Portobello (city bowl) has many GF options
Col'Cachhio (city bowl) GF pizza, amazing!!!