Another Frankenstein situation created by SKY/RFL, Roy. Back in the day, players were on a match fee/weekly wage that COULD be supplemented by a win bonus. Some PT teams may still operate this system but it's been ditched by the FT ones. They use the SKY cash to build a big enough squad (within the cap - usually).
Were they to leave a bit of wriggle room for win bonuses it would present a dilemma. Every club wishes to be successful, but OMG, we're going to win too many matches, pay too many bonuses and go over the cap. Call for the coach. Tell him to play the (no bonus) kids for the rest of the season - hopefully everyone will be doing the same and our kids'll be better than theirs.
Salford got a 6 point penalty for breach. Leigh would get at least 10. The in crowd might get a 1 point bonus, to be awarded at a time of the RFL's choosing (ie when they are neither in danger of relegation nor in contention for honours.
Sad situation created by the powers that be.