Query terms boosting


I want to increase a significancy for some terms in the query. E.g. increase term 'iphone' in phrase 'I like iphone'.
The recipe i found so far is 'query_string':

"query": {
"query_string": {
"query": "I like iphone^5.0"

The first question is do I loose the 'analysis' for this query. I mean if I set up stemmer will it work? Or for that kind of query the string will be processed 'as is'.
And the second - Are there better ways to do it? Should I use boolean query with term boosting instead?