Wildcard queries (the one ending with *) have some logical problems when language specific analysers are used.
If your document contains the word "organisation" lucene will stem the word and put "organ" into the index.
On the other hand if you search for "organisation" lucene will internally search for "organ" instead and therefore finds your document. It also finds document containing "organisations" - and that' the reason we prefer language specific analysers.
This however is not the case for wildcard queries. In you search for "organisation*" your document will not be found.
We now handle wildcard queries the same as normal term queries.
If you search for "organisation*" we now first use the analyser to stem the term and internally search for "organ*".