You may provision your device with both the standard and enterprise programs, and install their individual provisioning profiles to build your app with. But you'll have to sign your app differently because the provisioning portal generates different app IDs for your app for each account.
If you'd like to test that provisioning profiles work correctly with different developer program accounts, you can duplicate your existing build configuration profile by Control-clicking your Xcode project, choosing Get Info, going to the Configurations tab and duplicating a configuration. Then sign one configuration against your standard provisioning profile, and sign the other against the enterprise provisioning profile (go to the Build tab and look under the Code Signing section). Once ready to test your app on your iPad, pick and build as necessary.