Just to clarify, I'm a Spurs fan.
I'd agree that Spurs got lucky with some decisions against City in the two games at the Etihad. Plenty of Spurs fans would claim that that only evens out bad decisions to have gone against them in previous games against City. The 4-1 at WHL last season should have been 2-0 to Spurs (with three "goals" chalked off for offside). As to Alli's goals against City this season, he was comfortably onside for both of them. Perhaps you're thinking of someone else?
If you say that City have consistently suffered from poor decisions throughout this season, I won't argue. I haven't seen enough of your games to know otherwise. But, having watched all of Spurs' games, I can say that I have seen no evidence of them being consistently favoured by referees, as you claim.