TexasCHLforum.com

Your post is rather vague, but short answer, if the bus, is a munincipality, in Texas, carrying is not illegal. No need to lock up your gun. As far as your employer, if you have been told, that carrying is prohibited, you have been given effective notice. But, it will more than likely only cost you your job, if caught.
You have brought up an interesting conundrum, in that people who drive to their jobs, can leave their guns in their personal vehicle, in the parking lot, but those who take public transportation, have no option, but to either commute unarmed, or, violate company rules, about carrying.