Here's what I'd recommend:
If you've linked the WordPress installation to your Blubrry account, unlink it:
Go to PowerPress >> Settings, Advanced Mode >> Services & Stats and click the "Click here to Configure Blubrry Services" button. Enter your Blubrry credentials into the popup window and click the Remove button. This is necessary as it'll ensure none of your shows accidentally get tracked under the wrong stats.
Set up your two different podcast categories and then go to PowerPress >> Category Podcasting and check the box next to Strict Categories and click the Save Changes button.
Click the Edit link underneath the title of one of your category-based podcasts on the main Category Podcasting page. Copy/paste the stats redirect URL for the appropriate show into the Redirect URL in the Other Settings tab and click the Save Changes button.
That should apply the appropriate stats redirect for each category podcast, so as long as you publish the correct podcast under the correct category, each podcast will get the correct stats. You'll need to log into your account on the Blubrry website to view your stats for each show, and if you're using Blubrry media hosting, you'll have to upload your files thru the website as well, but it's the only option for these things as you have to unlink the WordPress site with the Blubrry account in order to make stats work with different shows.