It's not that VA has hit a foreign ownership limit, it's that Air NZ (AIZ) has hit the limit on the amount of VA shares that it specifically can by. In addition to the 25.99% of VAH that AIZ owns, Etihad owns 19.99% and Singapore Airlines owns 19.53%, according to the most recent ASX notifications. So those three foreign airlines alone own over 65% of VAH. I would assume total foreign ownership is well north of 70% (not sure how much Branson still owns?), and to the best of my knowledge, there is no overall limit on foreign ownership of VAH.
In contrast, as things stand, total foreign ownership of Qantas is limited to 49%, and the combined shareholding of foreign airlines is not allowed to exceed 35%. I'm generally not a QF or Alan Joyce fan, but this is one issue on which they have my sympathy, as it's clearly not a level playing field as far as international investment is concerned.