There are 2 sides to this situation. Presently, the bus division of the transport operators are making loses. In the new system, they will bid and ensure that they won't suffer loses. If they ever do, then it's due to their poor planning and probably mismanagement. Bus operation and frequencies will also be more consistent as they will have a set of rules to abide to, failing which I believe the LTA will penalize them with fines.
The government will be able to control the fares since these will be regulated by them. If the government is sincere in maintaining affordability, they may use their coffers to cross subsidize the bidding and maintain the fare structures. Otherwise, they will just increase the fares to compensate for the higher bidding by the transport operators. 1 advantage is that there may be more bus operators (than the current 2) bidding in the system, hopefully making it more competitive.
I believe the government had already planned for this when they approved the S$1.1bn package last year to purchase new buses and trains. So, they are smart because majority of the assets from this S$1.1bn amount will flow back to them again. However, I have no confident with those ass holes in LTA to technically manage the fleet well. So, be prepared Sinkies.