Injuries mean the 19-year-old has started the last two games alongside the Paraguay international and was man of the match in Saturday's 4-0 FA Cup win over QPR.
Stones has made just nine appearances this season but has hardly put a foot wrong when called upon due to the squad beginning to get stretched.
Manager Roberto Martinez last week said the England Under-21 international was "going to be one of the best defenders in the English game," and Alcaraz fully agrees.
"John was great. He is a young lad who has a long future and he had a great game against Stoke and QPR," he said.
"He has a great future, he has really good quality.
"He is a young guy and he needs more games to prove himself. If he carries on playing that way he can make a good impact on the Premier League."
Stones, a £3million signing from Barnsley almost a year ago, is enjoying his run in the side and admits he is learning plenty from the experienced trio of Alcaraz and the currently injured Phil Jagielka and Sylvain Distin.
"Antolin is a great footballer. You can see he is so calm on the ball and I thought we gelled quite well in the two games we have played with each other," he told evertontv.
"Jags and Sylvain are top players so I hope it is rubbing off on me and Antolin. They speak to be day-in and day-out giving me advice.
"Hopefully I will become a big fans' favourite here. I love the club to bits."
Alcaraz is finally starting to prove his worth to the side having been sidelined by injury for five months since he followed Martinez from Wigan in the summer.
He made his first competitive appearance in the 2-1 win over Southampton on December 29 and has played every minute of their subsequent two games.
"It is never easy. I am working hard to make it easy," Alcaraz said.
"To come back from a long period out is never easy but the players have helped me a lot.
"It is different and I try to do my best and enjoy it."
The 31-year-old played a key role in Wigan's FA Cup final win over Manchester City in May and he wants to return to Wembley once more.
"It was a good memory to go the final last year and one I want to repeat again. It was great," he added.