Dunno about Apple's Dev Program. I've taken undergrad CS courses a decade ago, and this seems to be on par given the same time span.
However, we started off with C, then 2 semesters of C++, then a sem. of Java. I hear these days, newcomers are going right to Java. However, my 1st semester of programming also had a lot of principles too, like efficiency, data structure comparisons, sorting/searches (log n, bubble sort, etc.). Also stuff on how to compile, use Unix, etc. It seems like this curriculum splits that up into 2 semesters?
That certificate is like a 4 year college comp Sci degree (I guess). It seems to be 18 credit hours of CS. I'm not sure what a 4 year college's credit hour requirements would be, but it might be more than that.
If I was looking to hire a new graduate I would prefer a 4 year college degree to a 2 year college degree. And I would like to see an interesting portfolio of iOS projects that the candidate had worked on.
I'd agree with this too. However, I wouldn't suggest the OP go out of his way in terms of student loans, debts, other expenses, and time spent just to get a 4-year degree if it'll cause unacceptable levels of hardship. Dunno just how much of a difference makes concerning a 4-year degree vs. a 2-year degree, and whether or not which is the better value for the time and $$.
Then again, I'm not well versed of the hiring situation this day in age for developers. AFAIK, you definitely want to have a portfolio set up so that HM (hiring managers) and companies can review your work, skills, and knowledge.
10 years ago, I've known a coworker who did journalism as her undergrad, learn Java (somehow), and get her masters in comp sci. She also got a Sun Certified Java Programmer cert, and definitely learned a lot on that job. Doing pretty well now.