As a general rule, no, unless I'm doing so to make a point / be heard. For example, I'll often verbally take a note of book recommendations that people give me, both to preserve the note for myself (as book recommendations are serious business) and to affirm to them that I am taking their recommendation seriously without having to explain that I am taking their recommendation seriously.

Beyond that, I agree that verbal commands on a bus would be inconsiderate both to the other passengers as well as the recipient of the message, whose privacy I just (slightly) violated. That said, if I'm sitting on a bus, I don't really have a good excuse for not typing the message myself, and typing is still slightly preferred except for when my hands are occupied or my phone is not conveniently accessible.