I have a Xamarin.IOS project that I created with my Windows Visual Studio.
With VS connected to my MacBook, I run the project on my iPad connected to my Mac.
I want to send my teammate the Windows Xamarin.IOS universal project so he can run it on his IOS device (iPhone) and test it?
Answers
Of course he can. If you don't want to share your paid Apple account with him he could use his own free or paid Apple account to test this project.

Here is documentation introducing how to use free provisioning profile for Xamarin.iOS app:
https://docs.microsoft.com/en-us/xamarin/ios/get-started/installation/device-provisioning/free-provisioning?tabs=windows
However, the bundle ID of your project couldn't be reused by a free Apple Account. So he needs to change the bundle ID of your project in info.plist here: