Howdy,
The patch in that ticket was not merged into Sunspot, for the reasons
I elaborated upon in my comment. However, Sunspot 0.10.6 does add
support for phrase slop and query phrase slop, which are the DisMax
query parser's implementation of proximity search. You can read about
those methods here (query_phrase_slop is also available as an option
to the fulltext() method):
http://outoftime.github.com/sunspot/docs/classes/Sunspot/DSL/Fulltext.html#M000049
Mat