Zoko, who was first borrowed from Championship side Blackpool back in November, will extend his loan deal with Phil Parkinson's men into May, while Halliday is expected to join City on a permanent deal.
Halliday originally moved to the Bantams on loan from Middlesbrough in October but he is now set to leave the Riverside Stadium and sign a fresh short-term contract with City.
Speaking in his press conference ahead of this Saturday's mouth-watering F.A Cup tie at Premier League leaders Chelsea, Parkinson said: "They (Halliday and Zoko) are both signing again.
"Zoko is signing on loan onto the end of the season, Halliday is signing a short-term deal.
"I'm pleased with that because I wanted to tie both of them up.
"They will both also be available to us for the weekend (vs Chelsea)."
Subject to the relevant paperwork being completed and cleared, both Halliday and Zoko are now in line to take their places in a fully-fit squad for Saturday's tie at Chelsea.
Part of City's travelling party for the eagerly-anticipated match will also include striker Billy Clarke after the Irishman recently recovered from a knee problem.
Parkinson added: "Everybody is fit - the treatment room is empty.
"It is great for me as a manager to have a full squad to select from.
"Billy Clarke, who has been out a few weeks with a medial knee ligament problem, is back in training now - that is a big bonus for us.
"At the time he got injured, Billy was probably one of our best players.
"He is available now for the weekend, which is great for us."
City goalkeeper Ben Williams, who is set to start at Stamford Bridge, has also now penned his new eighteen-month contract at the Coral Windows Stadium.