It is paid out in year one. You have to think in salary cap in terms of multiple year impacts though.
The actual money, in the case of a signing bonus, is paid in year one to a player. However, the salary cap implications of that bonus have impacts over multiple years.
Signing bonus, for cap purposes, is spread out evenly against the life of the contract. That bonus money cap hit effectively reduces the amount you can spend in future years of that contract. Then, if a player is cut, that bonus accelerates against the cap immediately. You get enough those things adding up, you're essentially lowering the amount you can spend, via your salary cap limitations, on a year by year basis. That ESPN article I posted does a great job of showing how it happens.
Dallas further compounds it by renegotiating almost immediately and even yearly in some instances (see Tyron Smith, Travis Frederick, etc.) to continue to push those bonus hits into future years.
Bottom line - Dallas has been in the bottom of the third of the league in cash spend since 2013 (I found 2017 too - they were last in cash spend). They have been cap constrained for the last several years. They do contracts and renegotiations unlike anyone else in the league. You could certainly argue a whole bunch of things: Romo's contract, bad contracts in general, poor personnel evaluation (resulting in bad contracts), unexpected injuries, the steps were necessary to maintain competitive with a tight salary cap......or maybe they've just realized they can use salary cap accounting to manage their annual operating expenses?
Whatever the case - I don't agree with the narrative that Jerry would spend whatever it takes to win. They just haven't spent as much as most teams since 2013. They're basically forced to spend this year since they are one of only 4 teams under the 89% spend threshold in the rolling four year window (2017-2020). Maybe they're out from under the Romo contract and things change now though.