Month year text matching

we’ve been using Sphinx for a while and recently we found out about Manticore. We made a test and seem fine, but we still have an issue, let me explain: we index some documents and some users search them by date, like ‘June 2015’, so we made a full-text field with the date. But we found out that some use also 'June ‘15’, so the shorter year form. Someone suggested to use synonyms (you call them wordforms) to have 2015 match with 15, 1999 match with 99 etc. Works mostly ok, except sometimes we get documents that are from a different year. After some digging, we come to realize the different year was coming from matching another field, which contains an identificator, something like ‘15 003 832’ (and some copy&paste this in the search box, we can’t take out the spaces). Any ideas?

I suspect you have a single search form, otherwise that would be just a matter of ‘@mydatefield June 15’.
A way to solve this is with wordforms, but map both words, like June 15>June 2015 (this wasn’t available prior 2.2.4)