Most commercial jobs have a bid spec sheet which will tell you what they want you to bid on. Other than that, I ask the maintenance guy or whoever is in charge. I will run through the list....Like, I assume you would like us to do the trimming and pruning and so on. I bid accordingly. I sometimes include optional items such as seasonal color(annuals) and aerating and overseeding.
Asking these questions has got me the previous contract a few times. They have always blocked out the amounts but a few times I have seen the numbers the other company submitted.