McAllister, who was a free agent after being released by Shrewsbury at the end of last season, last week signed with Micky Adams' men until January.
The 25-year-old midfielder was an unused substitute for the goalless draw at Southend on Saturday and is looking forward to winning a place in the team to show what he can do.
"Once I do get an opportunity, I'm confident I can impress and win a longer deal," McAllister told the club's official website.
"I'm here until January and it's not a great feeling to have such an uncertain future but I certainly don't want to be in the position I've been in over the last two months again, spending the summer ringing around clubs looking for someone to take me.
"Finding a club as an out-of-work footballer was a lot harder than I thought but I couldn't have found a better team to go to, with Vale second in the league, so I'm delighted to be here and I can't wait to get on the pitch."