They sat in last place before the sacking of ex-boss Ernie Merrick and remain in eighth despite picking up five points in their last three games.
"At the moment, for me, they're offering the A-League nothing," Bosnich said.
"I want to see a bit of consistency and them actually threatening to get into the top four, instead of struggling around the fringes."
The Nix, despite financial stability under the local Welnix consortium, received a scare last year when a 10-year extension of their A-League licence was denied.
The license was later extended in February, with the club obliged to improve its broadcast rights, viewership and crowds in New Zealand.
Those metrics will be reviewed by Football Federation Australia in 2020.
Bosnich said the public outcry of support for the Phoenix on both sides of the Tasman during that saga may have been for naught.
The side would have to play more like two years ago, when they finished the league in fourth, to have any hope of remaining in the competition.
"The mind beggars with them, I really don't know what to say," Bosnich said.
"We had that thing, keep Wellington in the A-League and everyone got behind them, and all of a sudden it's all dropped off."
Co-pundit and former Sydney FC skipper Mark Rudan was equally scathing post- game, criticising Barbarouses for his comments on the side's uptick in form.
The 27-year-old Kiwi winger said the departure of Merrick and a change of formation had galvanised the side.
"If I was Ernie Merrick listening to that, I'd be extremely disappointed, knowing it took him getting the sack to get a reaction," Rudan said.
