Yes, as I understand, SCL did exist at one point, years ago. I think some combination of competition against Lan and other performance issues led to its demise. The closest CO serves is EZE.

Skyteam IAH options to SCL involve DL via ATL (with very good reviews from my parents) and CM via PTY (I personally took the PTY route). AM also offers service, but the others usually have better fares and schedule options.
Another probably better option for the IAH bound would be AA's DFW service.