Easiest way to complete this is to load up any Bullring besides Grassland. I found La Macarena worked very well. Taunt the bull by pressing RB. As it is heading towards you, hold LT down and press X,X. This will do the Veronica move. You will need to string a combo of 7 for the achievement to unlock.
Note that on the string of 6, the bull will not need a taunt [RB] and will charge you on it's own, so be ready.