How to promisify your own javascript api which uses another promisified api with Bluebird?

I'm struggling with this a bit. I want to build an abstraction layer over a database driver module in node. I've already promisified the driver module by doing the following:

var sql = Promise.promisifyAll(require('sql-driver'));

Then within my own js file I want to wrap queries like so:

function query(queryString) {
   sql.connectAsync(config).then(function() {

      var req = new sql.Request();
      req.queryAsync(queryString).then(function(resultSet)) {
          console.log(resultSet);
      });
   });
}

How can I promisify (using bluebird) so that my query function is also promisified and returns a promise or thenable?