Hm, the real estate growth is actually mostly private. One of the reasons is this:
http://goldenvisa-portugal.com/FAQ.html
which is confirmed by this:
https://tradingeconomics.com/portuga...ownership-rate
Buyers are mostly foreigners, home ownership among the Portuguese isn't really moving.
Government fixing infrastracture certainly helps.
If this turns out to be a bubble, it shouldn't burst before 5-6 years, and even then, I read somewhere mostly German and Dutch banks are financing it, they are the ones that will have major imbalances in accounting.
Portugal, depends: ideally you should achieve government surpluses years before the bubble bursts. If you do and the bubble bursts, you find yourself flat or slightly in deficit but noone will care. If you run deficits until the bubble bursts however, it'll be 2008-9 all over again.