Last year I was flying with Iberia, stopover in Madrid. I booked well in advance, and paid around CHFr 250.- return. Iberia is also offering flights with stopover in Barcelona.
Air Berlin are offering flights to Zurich from Santiago via Palma de Mallorca, and they are cheap!
I heard about a direct bus from Santiago to Zurich, but don't know about timetables etc. And it takes ages to do the trip by bus...
Thanks for the responses, just to confuse matters I would actually be looking at Santiago - Zurich - London, although I guess I could do return to Santiago and RyanAir back from there. I guess this confirms there are no easy connections though!!
First - to get to Santiago, I´m in Hospital de Orbigo now and it seems a very long way away still...
The problem with AirBerlin is that it doesn't arrive in Zurich at a very sociable hour if one still needs to take a train connection from there. The route that I eventually took was ClickAir via Barcelona - it arrived at a decent time and was cheaper than AirBerlin too - just take something to read for the time at Barcelona airport!