Well, I wouldn't say you'll hit 4 minutes after a couple of hours (some people can/do, some people can't/don't), but you'll definitely be provided with the education in order to work on it. On these sorts of courses it's best to concentrate on learning the techniques rather than trying to hit a target - it can become frustrating for the student if they've got a number in their head they want to achieve and they struggle to get there. What they don't realise is that probably after a month or so that number they had in their head will be well surpassed.
I had a look at Erez's website and it looks like he'll be back in September, if you wanted to do a course sooner. It's funny - Australia has had no qualifed freedive instructors before and soon enough there will be 3 all in South East QLD within an hours drive of each other! My excuse is that my wife wants to live in Brisbane.... not my call

But hey, all that sunshine and blue water can't be all bad
Cheers,
Ben