All the Apple Watch Fitness+ features now work when accessing workouts on an iPad. It means that users do get the same data on the larger screen as when they conduct a session on an iPhone.
All Apple Watch Features work on Fitness+ on iPad
As previously reported by The Mac Observer, there used to be a bug that stopped Fitness+ subscribers following sessions on an iPad from using the Apple Watch capabilities available with the service. That was not resolved with the release of iPadOS 14.4. However, I reopened the service over the weekend, having signed up for the Premier Apple One bundle. It all worked with no syncing issues, meaning that my heart rate was monitored and other analytics were made available during the session. This is a significant step forward in making the service more usable.