What is the recommended wordpress backup strategy?

Nope. That gives you your WordPress app files (that you can download again from WP at any time), your plugins and your themes. Certainly helpful, but you won't have any of your data -- Posts, Pages, configuration, etc.

Learn more at http://codex.wordpress.org/WordPress_Backups

You'll probably want to look for a backup plugin that will help automate the backup process -- many will even email you the actual backups for storage. Look through this list: http://wordpress.org/extend/plugins/search.php?q=backup

Hope that helps.

You need the database as well -- that can be accomplished with a combination of cronjob and mysqldump (assuming you're using MySQL) but I think there's also a plugin for Wordpress that handles backup if I recall correctly; do a search through the community add-ons section.

http://wordpress.org/extend/plugins/wp-db-backup/