I checked online and it seems wistia does have their own analytics features: https://wistia.com/product/analytics?ft= so you might want to look into it a bit further.
I personally never worked with this player but I worked on other analytics milestone tracking in the paste and you can find details in this repo if it helps:
Legacy Video Milestone implementation:
https://github.com/alcazes/Video-in-Adobe-Analytics-V15/wiki/Home---Adobe-Analytics-v15-and-Video-Mi...
https://github.com/alcazes/Adobe-Analytics-Video-milestone
Video Heartbeat:
https://github.com/alcazes/Adobe-Analytics-Video-Hearbeat
All of this documentation is a bit old but might help. In all instances you need to use the exposed lifecycle functions of the player or its API to send data at correct time.
Which library you are currently trying to use ?
https://github.com/alcazes/Adobe-Analytics-Video-Hearbeat