I'm not sure if you are asking about running a playground on an iPhone or if you are asking about running an app you wrote with the Mac version of Swift Playgrounds on an iPhone. But the answer is the same either way. No, you won't be able to run your code on an iPhone.
Swift Playgrounds is available for iPad and Mac, not iPhone. You are not going to be able to run playground code that is not an app on an iPhone. You could run the code on an iPad if you install the iPad version of Swift Playgrounds.
The Mac version of Swift Playgrounds makes Mac Catalyst apps, a Mac version of an iPad app. You are not going to be able to run an app you make with the Mac version of Swift Playgrounds on an iPhone.
My suggestion is to continue learning to code using Swift Playgrounds on Mac. When you are ready to make an iPhone app, create an iOS app project in Xcode.
Topic:
Developer Tools & Services
SubTopic:
Swift Playground