Hi hdxx
Personal mastery focuses on you growing as an individual and knowing what to learn and how to learn, while team learning is about team members sharing ideas and views to develop solutions to complex problems. Imo, there is no clear difference between the two principles that i can point out except for that while personal mastery relates to business growth through personal growth in individuals, team learning relates to business growth creating teams of people.
Systems Thinking refers to a management and operations approach where single business decisions are analyzed based on the systematic consequences they have. In other words, being able to foresee the consequences of decisions and able to analyse a poor consequence in terms of how it occured.
Hope that helps