@Henrick, Brad Jeffrey, Thanks for posting in Q&A.
Based on my research, currently, Intune does not support applying Quality of Service (QoS) tagging directly to the Microsoft Teams mobile app on Android and iOS devices in the same way it does for the Teams desktop client on Windows PCs.
Also, I have discussed with our Microsoft Teams support and find that there is no such setting in Microsoft Teams on Android/iOS device can implement QoS, so, Intune cannot create such policy to do that before it implements in Microsoft Teams on Android/iOS device and you can submit your feedback to Microsoft Teams to implement this feature.
https://feedbackportal.microsoft.com/feedback/forum/ad198462-1c1c-ec11-b6e7-0022481f8472
Thanks for your time and understanding.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.