The emails sent to your aliases arrive directly in your usual inbox.
Whatever email address you use to log in to your Pocket Geek ID account is the one where the emails sent to your aliases are forwarded.
You may have registered to Pocket Geek ID directly or you may be using credentials from your original provider. In any case the email address you use to log in is the final destination for all the mail received through your aliases.
If you are unsure of which inbox your aliases are sent to, you can always find this information by going to the Profile tab of your "My Account" page.