Within Corporate (which all 3 tracks fall under), the values are upheld very well and the culture is incredibly positive. More senior team members are generally willing to coach newer team members and I would definitely not consider it a high pressure work environment or one with toxic relationships between team members. Wells is a huge bank though and as seen in the news there are areas in the bank such as certain retail branches where it does not appear the culture was a positive one (there is a strong push right now to bring the cultures of the various lines of business into alignment).
Quite frankly, everyone I worked with was completely shocked when the news first started coming out about the retail bank's wrongdoings because in our department the compliance was extremely tight. I don't think Wells Fargo is very different from their US large bank peers.
I really enjoyed working at Wells Fargo last summer which is a large reason why I decided to return full time. I believe Wells Fargo has taken ownership for the mistakes they have made and are taking all the necessary steps (and more) in order to rectify these mistakes. Nobody I worked with at the bank tried to deny or cover up any of the wrongdoings, and instead, they discussed and stressed to us what was changing and how they were going to improve. The bank revolves around the customer, and that was emphasized to me every day.