Is money earned from promoting halal products that contain music considered unlawful, given that the target audience is non-Muslim foreigners, and can this be compared to the earnings of a transport driver who plays songs?

If the discs contain health advice and unintentional musical sounds, then what you earn from promoting them is permissible. Directing the advertisement to non-Muslims does not affect the ruling; for what is forbidden is not permissible to sell to either a Muslim or a disbeliever.