I would find a Latin language stemmer very helpful. The Schinke Latin stemming algorithm has been converted to Snowball here: http://snowball.tartarus.org/otherapps/schinke/intro.html . I have not worked out how to compile Snowball into .cs to try it.
There are currently 5 romance-languages supported (French, Spanish, Portuguese, Italian, Romanian). so if the above doesn't work, I imagine one of these could be modified to support Latin.
I realise SF.Snowball is considered a contrib package rather than core, but Lucene.Net seems to be the main place where Snowball stemmers are provided and maintained for C# / .Net.
Note, other language ports of Snowball support Latin (using the Schinke contribution), such as Ruby: https://github.com/aurelian/ruby-stemmer