How does Cohagen track Quaid after the bug is removed?

I can only speak for the 2012 remake. They find him in his old apartment building and try to persuade him he is still at Rekall. If he is trying to figure out who he is, it is a logical assumption for those hunting him that he might end up at his old apartment to look for clues. His apartment is sealed by police tape, so the apartment or building could very easily have been under some type of surveillance. Also, he was carrying an unconscious Melina through the building and entering an apartment that was taped off by the police. People in the building could have reported this. So, it could be that they had a hunch he would go there, and verified he was there by people witnessing him entering the building carrying a woman. Or, the apartment was under surveillance in the first place. Melina did say that they shouldn't have come here, so it seems they would have been found there eventually for any of the above reasons.

In the 1990 film the explanation is pretty clear: Quaid create his alternate persona and simply informed Cohagen of the plans that he made. That way even when Quaid had removed the hidden transmitter from his bead, Cohagen would still know that Quaid plan entailed him infiltrating the Resistance and eventually returning to Mars. This would have tracking him relatively easy as Cohagen had inside information about his plans.

Cohagen also employs operatives (such as Benny the mutant taxi driver) who keep track of Quaid when he's on Mars. That way, even Quaid were to somehow figure out that his change of heart was really a ruse, there were already agents in place to track his movements and inform Cohagen as to where and later Kuato, leader of Mars's underground mutant resistance, were located.

The 2012 film is is even easier to understand as there were only two places where Quaid could be: The UFB or The Colony. Since there is no space travel and the rest of the Earth was a poisoned wasteland, Quaid was either in one or the other and as shown Cohagen had agents in both. Also, it can be surmised from the later video showing Quaid and Cohagen together that Cohagen knew about the entirety of Quaid's plans in advance.

Side note: While it's clear in the Philip K. Dick source novel We Can Remember It for You Wholesale That some of Quaid's (in the novel his name is Quail) memories are clearly fabrications, both film versions are portrayed as straight recitations of the events which occur. In both film narratives, Quaid is prevented from undergoing the Recall/Rekall memory process and, as such, is living out the events which unfold.

Total Recall 2012: The answer relies on the kid he traded his phone with. The "wife" makes him tell her what he knows. How does he know? He heard the open phone call while Quaid was talking in plain sight of everyone. After that I'm not sure...

I have not seen the remake but I remember in the original the entire thing was in Quaid's mind. The evidence is when they are putting him under and they ask him to describe his perfect girl and he says something like 'brunette, athletic, sleazy' and on the monitor they show Melina, the girl he meets later in the bar.

Either they happened by co-incidence to show a model inspired by what Quaid said which looked EXACTLY like a random girl on a different planet which he later met or it was the same girl and everything from then on was a part of Quaid's dream state - which is why is pretty much happened exactly as described in the sales pitch.

Once you consider that then it makes sense that Cohagen's men would find Quaid and there would be an exciting fight sequence where he out-smarted and out-fought everyone as that is what he has paid for.

PS - please do not downvote this because you do not agree he was in a dream state unless you have any evidence for why you think I am wrong and do not forget that I am referring only to the original, I have not seen the remake.