Arvonia Coaches driver Sean Davies, 51, was filmed using the handheld device during a 10-day trip to Croatia last July.
Footage shows him staring at and tapping the screen for prolonged periods, barely looking up at the road ahead.
Balancing the device in the middle of the steering wheel, he casually steers the huge vehicle down a Belgium autobahn.
William Jones, from Llangefni, Wales, spotted Davies' shocking lapses of concentration and filmed him on several occasions during the trip.
In one sequence, the vehicle was driving in heavy traffic along a motorway at speeds of over 60mph.
Rain poured down as he approached roadworks while looking at his phone.
Another clip was filmed in the driver's rear view mirror and showed him apparently using the phone and only glancing up at the road ahead.
Now Davies, from Colwyn Bay, Wales, has had his bus driving licence revoked and been disqualified from applying for another for 12 months.
Traffic Commissioner Nick Jones viewed the damning video clips in private and Davies told him he did not dispute the footage at a hearing in Welshpool on Friday.
'I very much regret what I did on that day,' he said.
'I have worked in the industry for 28 years and am very embarrassed and very sorry for what I have brought on the company.'
Davies said he had worked for Llanrug-based Arvonia Coaches for 14 years but no longer worked as a coach driver.
The Commissioner said he was seen to look down at the device 'for worryingly long periods'.
Davies claimed these periods were 'two seconds usually', to which the Traffic Commissioner remarked: 'That's long enough.'
Announcing his decision, the Traffic Commissioner said: 'What you did was not a single isolated incident.
'The use of a mobile phone is unacceptable and you used it on at least three separate occasions which is wholly unacceptable.'
During the 90-minute hearing, Mr Davies claimed he had concerns about the personal safety of Mr Jones during the journey.
He said he had seen Mr Jones stand up at the front of the coach and that he had twice refused his requests to sit down.
Mr Davies had then shouted to Mr Jones as he was concerned that, if he had to brake suddenly, he would have struck the windscreen.
Arvonia Coaches general manager Sean Stokes said he overheard a conversation in the Llanrug office between the passenger and a staff member.
'The gist of it was she felt he (Mr Jones) had it in for the driver and was looking to cause trouble,' he said.
Following a report in the Daily Post in October, the company was visited by Driver Vehicle and Standards Agency (DVSA) inspectors, and the Traffic Commissioner summoned Arvonia Coaches directors Rhiannon and Marcus Stokes to the public inquiry.
He said the DVSA report was 'mostly satisfactory' and if the phone incident had not been reported it would not have led to a public inquiry.
'Many accidents are caused by driver error, be they tiredness, drug or alcohol use or being distracted,' said the Commissioner.
'The use of a mobile phone is exceptionally dangerous and I would expect all operators to have policies in place regarding the use of mobile phones.'
Laura Hadzik, solicitor for Arvonia, confirmed there was no written policy in place at the time but one had been introduced since the incident.
She added this was now part of the driver's contracts of employment.
The Traffic Commissioner was concerned that Mrs Stokes, as transport manager, had not attended refresher training when she might have been advised of good practice with regard to mobile phones.
But Ms Hadzik said the incident had led to a company review and Mrs Stokes intended to resign as transport manager and hand over that responsibility to her son Sean.
Noting the family-run coach tour business was highly regarded and had not been before a public inquiry before, the Traffic Commissioner issued Arvonia Coaches with a formal warning.
Davies left the inquiry without making any comment.
Photo: Daily Post Wales