Can't get .scss file out of gulp-main-bower-files

Question

I am using the gulp-main-bower-files plug-in to get the main scss file out of the bootstrap-sass folder. Here is my task code:

   gulp.task('bower-scss', function() {
    var scssFilter = gulpFilter(['**/**/.scss']);
    return gulp.src('./bower.json')
    .pipe(mainBowerFiles({ 
     overrides: { 
        bootstrap: { 
          main: ['assets/stylesheets/_bootstrap.scss'] 
         } 
       } 
     }))
    .pipe(scssFilter)
    .pipe(gulp.dest("dist/vendor/scss")

});

However, when I run gulp, it does not seem to copy the scss file into the scss directory. How can I get it to work?