If you and your partner have lived together for at least 365 days (continuously) and have sufficient proof, you can submit an Inland application.
Even though an Outland application is probably faster to process, the Public Policy that allows for those without status to apply for sponsorship, apparently only pertains to those that submit an Inland application. Having said that, there have been a few that submitted an Outland application, and were approved, while other Outland applicants were told to leave Canada, since they did not have valid status.