Went to Santiago in 2010. It was not a beer vacation per se, but I found lots of good beer there. You can find all styles of beer there, but you’ll notice a definite German influence.
We did find time to do a brewery tour to Kross brewery just outside of Santiago. It was excellent, though they didn’t really understand why we would want to look at their facility. The head brewer looked at us kind of sideways, but after the tour he started pouring for us and then didn’t want us to leave. I would recommend their beer highly, and who knows, maybe the brewery tour thing has caught on by now.
They love their beer there and have plenty of it, so I’m sure you’ll have a good time. Let me know how it goes.