The text attribute of the CuramQuery class is an alternative to a set of terms and allows more flexibility in specifying your search criteria. It should be used only if required as it is also easier to introduce bugs in your searches with this approach. The format for specifying search criteria using this attribute is described in the Lucene documentation. This is available at http://lucene.apache.org/java/2_2_0/queryparsersyntax.html.
You cannot combine Terms and the use of the text query string. If the text query string is present then any CuramTerms present in the query will be ignored.