.bowerrc

{
  "directory": "vendor/bower_components"
}

bower.json

{
  "name": "Laravel Application",
  "dependencies": {
    "bootstrap-sass-official": "~3.3.3"
  }
}

gulpfile.js

var elixir = require('laravel-elixir');

/*
 |--------------------------------------------------------------------------
 | Elixir Asset Management
 |--------------------------------------------------------------------------
 |
 | Elixir provides a clean, fluent API for defining some basic Gulp tasks
 | for your Laravel application. By default, we are compiling the Less
 | file for our application, as well as publishing vendor resources.
 |
 */

 
var paths = {
  'jquery': './vendor/bower_components/jquery/',
  'bootstrap': './vendor/bower_components/bootstrap-sass-official/assets/'
}
 
elixir(function(mix) {
    mix.sass("app.scss", 'public/css/', {includePaths: [paths.bootstrap + 'stylesheets/']})
        .copy(paths.bootstrap + 'fonts/bootstrap/**', 'public/fonts')
        .scripts([
            paths.jquery + "dist/jquery.js",
            paths.bootstrap + "javascripts/bootstrap.js"
        ], 'public/js/app.js', './');
});