It looks like your referer test contains a couple of *. Since it’s a contains, I’d leave it as just ‘website’. I’d also use a ‘contains’ for ‘wp-comments-post’. I try to simplify it as much as I can.
If it’s bots, why not try JS Challenge for URI Contains wp-comments-post.
Or…Gulshan Kumar has a plugin that’s supposed to be pretty good. Here’s his blog post with a link to the plugin and a detailed description how it works: