Answer:
It's an advantage for the bacteria, not an advantage for the salamander
Explanation:
The point of reproduction ideally is to produce as many offspring in as little time as possible, to increase the number of offspring that thrive. Therefore the bacteria being able to multiply quickly is an advantage and will most likely increase the chances of evolution occuring sooner (antibiotic resistant bacteria for example). The salamander having to wait 4 years to have few offspring will make the number of babies they're able to have in a lifetime rather low.