In Australia, establishments hires apprentices which are called first,
second or third year apprentices. The fourth year is when you are
already a qualified pastry cook but not a pastry chef. But if you
attend also formal education in patisserie while you are still doing
your pastry cook apprentices you will end up in the end as a pastry
chef. That is likely at least after 5 years from the start of your
apprenticeship. It depends also upon your aptitude, if you are fast
learner you can be pastry chef in less time specially if you undergo
training from a well known pastry chef.
There is not that much in Australia what I call highly qualified
pastry chef. In fact most of the pastry chef that are really good are
educated in Europe and came in as immigrants.
A pastry chef is really capable if he has attained at least decade of
experience and most of that overseas.