I get two fan shaped jets of screenwash about quarter of the way up the front windscreen.

The rear screen washer fires a single vertical jet that washes the vehicle behind.

I used to stick a pin in a spherical jet and push or pull it until the required effect was obtained,

with my other cars, on this one I cannot even see the little tinkers.

perhaps this

 

http://www.briskoda.net/forums/topic/250227-windscreen-washer-adjustment/

And the rear one can be adjusted with a pin.

Thank you both, I assume the adjusting screw is reached from under the bonnet?

The adjuster is beside the jet, not under bonnet.....http://www.briskoda.net/forums/topic/153037-front-screen-washer-jets-adjustment/