I'm using the iOS SDK to connect via a connected app to my SF environment. Is it possible to connect the app to a second environment at the same time?
The Connected app is actually NOT connecting your mobile app to your Salesforce org. It is merely determining what callback URL, access permissions etc. your app will have based on the Connected app configuration. You can refer to some of the explanations on this thread or a more detailed response on this thread.
This was also discussed on Developer Forums where the Mobile SDK team described this behavior.