I've been raised listening to many telling 'mastery on' some subject. Muhammad Ali had mastery on various boxing tricks. Serena has mastery on tennis strokes. Shakespeare had mastery on English and so on...
This constructive comment made me think again. As I dig in the dictionaries, they all have 'of' preposition. This is very new to me. I shall use 'of' now on but I still find many examples that back my learning. I still feel that 'on' is not incorrect. 'Mastery on' is like having 'hands on', 'expertise on' and so on!
Dave also has a reputation as a fine songwriter and singer, in addition to his mastery on both electric and acoustic guitar from Connectstoughton (link not working independently)
Last year, 78 percent of AVID students at SSS showed mastery on the English II and math I exams from News and Observer
The idea that you might be able to demonstrate mastery on a certain subject, get credit for that from Hechinger Report
He’s taught master classes and clinics in more than 20 countries around the world, teaching jazz piano as well as sharing his mastery on producing and scoring music from Business Wire