@Matt ... Quick update ...
I replaced my header.php's <title> code with what you're using, but take a look at your Woocommerce categories and see if it displays the correct title. It didn't for me, so I combined ours and it works as it should.
Here's what I have:
<title><?php if (is_shop()){ echo "Shop Title Here!!! Yahooo";} else{wp_title('');}?></title>
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My particular set up is:
- Abundance theme
- Yoast's Wordpress SEO
- Code sample above for <title>