Add Vinyl FTP deploy to an existing gulp watch workflow

I have little experience with Gulp and just want to be able to automatically upload my css file immediately after Gulp has created it from my SASS files through gulp watch:css

I've tried adding the 'deploy' task into the gulp watch:css task, but I cannot get the deploy task to run AFTER the CSS file is created. It always runs before.

Here's the relevant code where I have tried to add 'deploy' to the gulp watch:css task...

gulp.task('watch:css', ['styles', 'deploy'], function() {
  return gulp.watch(options.theme.sass + '**/*.scss', options.gulpWatchOptions, ['styles', 'deploy']);
});

gulp.task('styles', ['clean:css'], function() {
  return gulp.src(sassFiles)
    .pipe($.sourcemaps.init())
    .pipe(sass(options.sass).on('error', sass.logError))
    .pipe($.autoprefixer(options.autoprefixer))
    .pipe($.size({showFiles: true}))
    .pipe($.sourcemaps.write('./'))
    .pipe(gulp.dest(options.theme.css))
    .pipe($.if(browserSync.active, browserSync.stream({match: '**/*.css'})))
});

var gutil = require( 'gulp-util' );
var ftp = require( 'vinyl-ftp' );

gulp.task( 'deploy', function () {

    var conn = ftp.create( {
        host:     'xxx.com',
        user:     'xxx',
        password: 'xxx',
        parallel: 10,
        log:      gutil.log
    } );

    var globs = [
      'css/styles.css'
    ];

    // using base = '.' will transfer everything to /public_html correctly 
    // turn off buffering in gulp.src for best performance 

    return gulp.src( globs, { base: '.', buffer: false } )
        .pipe( conn.newer( '/' ) ) // only upload newer files 
        .pipe( conn.dest( '/' ) );

} );

Figured it out...

the 'watch:css' task calls my 'deploy' task instead of 'styles':

gulp.task('watch:css', ['deploy'], function() {
  return gulp.watch(options.theme.sass + '**/*.scss', options.gulpWatchOptions, ['deploy']);
});

the 'styles' task remains as is

the 'deploy' task takes the 'styles' task as a dependency like this

gulp.task( 'deploy', ['styles'], function () {

Now when running 'gulp watch:css' it triggers the 'deploy' function on every change to my SASS files, which in turn triggers the 'styles' function that compiles my CSS.