2 syns for the 2 teaspoons of honey (1 syn per teaspoon of honey). This recipe is even more delicious if you buy honey with honeycomb in it and mash it all up. And instead of blueberries, try sliced strawberries.
By the way, BE CAREFUL WITH HONEY - lots of stores (especially international supermarkets) sell honey at cheap prices but when you read the ingredients - its a combination of honey and sugar/glucose syrup. Honey by reliable companies like Rowse are trustworthy to be the full thing.