Benitez's side clinched an immediate return to the Premier League following last year's relegation as a 4-1 victory over Preston on Monday guaranteed automatic promotion from the Championship.
Aware that Newcastle's hierarchy have often failed to provide the cash required to compete in the top flight in the past, the Magpies manager immediately seized on the opportunity to demand financial backing from a position of strength following promotion.
Asked if he would definitely lead Newcastle into the Premier League next season, Benitez coyly declined to answer and instead drew attention to what he anticipates will have to be a busy close season of heavy investment in the squad.
"You never know, that is football. But I am really pleased here, very happy and very proud of everything we have achieved," said Benitez, who signed a three-year contract last year.
"Hopefully we can put in the basement to do something that will be a guarantee for the future too. Now it's the time to enjoy, but I am sure that if we do the right things, we have to prepare everything to be strong enough for the Premier League."
The former Liverpool and Real Madrid manager's comments were undoubtedly meant to serve as a reminder to owner Mike Ashley that promotion is only the start of his mission on Tyneside and that he needs the club's backing to continue it.
However, he will allow himself, his staff and his players to enjoy their success for a few days after a rare season outside the elite for Benitez.
"I am really proud of everyone because we knew that was difficult. At the beginning when everyone was saying, 'Rafa has no experience in the Championship, it will be tough', it was right, it was very difficult," he said.
"But the commitment of the players, the hard work of the players every day, the staff, everyone involved and after, the support of the fans, has made a massive difference. It's a day that we have to remember because it's not easy to go down and go up first time."