Successfully complete the indicated task in Road To WrestleMania mode to unlock the corresponding bonus:

Champion Of Champions title belt: Play as Brand Warfare, and win at WrestleMania.
DX, Morrison, The Hardys, and The Miz tag entrances: Play as Brand Warfar, and win the Battle Royal with Triple H or John Cena in Week 2.
Road To WrestleMania Event Skip feature: Play as Randy Orton, and spend less than two minutes in the ring with the legal Superstar in Week 12.
Santino Marella Story Designer story: Play as a created Superstar, and reach 500 degrees at least four times in Week 11.