Someone robbed my phone on the bus.
Someone stole my phone on the bus.
Use steal + thing: ‘Someone stole my phone.’ ‘They stole some money.’
Use rob + person/place: ‘Someone robbed me.’ ‘They robbed a bank.’
We can also use steal something from + person/place: ‘Someone stole my phone from me.’ ‘They stole some money from the bank.’
See STEAL