You have asked this question twice Brivin. If you dont want confusion in the answers it might be a good idea to remove one?
I think they have to mature 4-5 years before you have real fruit? - so if you bought 2 year old bushes should fruit next year?
Black currants bear heaviest crops on one year old wood, with a lighter crop on second and third year growth. It is therefore important to ensure there is a plentiful supply of new growth to provide the following year's crop. In late autumn, prune back all shoots more than three years old. Also remove bent or broken branches, and those growing too close to the ground. Black currants are self-pollinating but will yield more heavily if a cross-pollinator is nearby? Blackcurrants need winter chill to fruit well and can suffer after mid winters in the south? Hope this helps?