Engineering is so centralised that college choice really doesn't make any difference. The admissions process is one of the most centralised out of any subject at Oxford (so much so that many other subjects are going to be using it as the model to follow in the next few years), so if you're worth a place at Oxford to do Engineering they'll do their darndest to get you one somewhere.
Having said that, the only college that I know of as traditionally being known as an 'engineering college' is Keble, mainly because it's next door to the department (as in, you couldn't get any closer if you wanted to) and takes around 10 students each year. As far as I'm aware, no colleges have reputations for being bad at engineering (or any other subject, come to that). Choose your college based on other, more important things, such as location, accommodation provision, atmosphere etc.