A lot of great art was originally sponsored/commissioned by wealthy corporate benefactors (for example the Catholic Church and nobility in 15th century Italy).
I think it's important that the beholder/public in general is aware of the providence of a piece of art, yet I doubt banning corporate sponsorship of art would be a net positive for society.
Additonally, I would say that the bull statue has well and truly earned its place. It is now an established piece of art: it has been subverted.