We rode the bus twice in Sydney – first to get from the city to Bondi Beach and the second to go to a train station from Bondi Beach. I wasn’t really able to get a lot of photos inside the buses as they quickly filled with passengers and I wasn’t sure what people thought about someone taking photos inside a bus even for touristy purposes. It is usually better to blend in with the crowd than attract attention to yourself; though it probably didn’t matter much since there were so many Asians in Sydney and wherever we went.
You can use the Opal card to pay for your bus fare.
Buses are laid out to optimize the number of passengers it could carry. There are just enough seats for those who need to be seated. Others have to stand but standing space is important for commutes.