Bath led 38-10 at the interval, with Tom Dunn, Tom Homer, Robbie Fruean, Kahn Fotuali'i and Ford all going over.
Samoan Fotuali'i crossed for his second try, as Rokoduguni and Chris Cook also scored at Ashton Gate for the visitors.
Tom Varndell, Rhodri Williams and Jack Tovey went over for Bristol, but they remain third in the pool.
Fly-half Ford, who has been strongly linked with a move to Premiership rivals Sale at the end of the season, contributed 20 points as Bath did the damage in the first half.
Fotuali'i's double on return from an eye injury was another plus, with Todd Blackadder's team five points clear at the top of their European Challenge Cup group ahead of Cardiff Blues' trip to French Top 14 side Pau on Saturday.
Bristol: Arscott; Wallace, Palamo, Pisi, Varndell; Searle, Williams; Traynor, Crumpton, Ford-Robinson, Phillips, Glynn, Lam, Robinson (capt), Eadie.
Replacements: Jones, Bevington, Cortes, Nemsadze, Joyce, Cliff, Jarvis, Tovey.
Bath: Homer; Rokoduguni, Joseph, Fruean, Watson; Ford (co-capt), Fotuali'i; Catt, Dunn, Lahiff, Ewels, Stooke, Mercer, Louw (co-capt), Grant.
Replacements: Walker, Obano, Palma-Newport, Douglas, Mercer, Cook, Priestland, Tapuai.
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Prime Minister Recep Tayyip Erdogan travelled aboard the first train in the service from Ankara, stopping at a town en route to make a campaign speech.
The tracks allow trains to reach speeds of up to 250 km (155 miles) per hour.
Mr Erdogan, a candidate in presidential elections in August, has pledged to overhaul Turkey's transport network.
"We made a promise. We worked hard. We crossed the mountains, and passed over rivers," Mr Erdogan said, at a campaign stop in the town of Eskisehir.
"Despite all the attempts of sabotage, blockade, and slowdown, we completed the line and opened it for service today."
The inauguration of the train link has been beset by hitches and delays, most recently when a train crashed into a maintenance vehicle.
The new service will terminate in the Istanbul suburb of Pendik, on the Asian side of the Bosphorus.
The government plans to build a further rail link, under the Bosphorus, to the centre of the city, but it is unclear when this will happen.

Small Business Saturday is in its third year, and aims to encourage people to spend locally rather than with international chains.
There are around five million small firms in the UK which employ half of the country's workforce.
The government said it wanted to help "cut red tape" for small businesses.
Business Secretary Sajid Javid said: "Small Business Saturday is an opportunity to come together and generate a real boost for small firms in the run-up to Christmas.
"Having grown up above the family shop myself, I'm proud of the UK's small businesses, providing jobs and security for millions of people and making a huge contribution to our economy."
Any firm with fewer than 50 employees is considered a small business.  In Britain 99% of all companies are in that category - employing 12.4 million people.
Last year UK traders took Â£504m on the day from an estimated 16.5 million people - a 20% increase in footfall on 2013.
But day-to-day small firms face a battle competing with big companies who can offer lower prices and have more resources to deal with issues such as administration, tax and staffing.
The Federation of Small businesses said that for every pound spent at an independent company,  around 70p stays in the local economy.
England internationals George Ford and Semesa Rokoduguni were among the try-scorers as Bath thrashed local rivals Bristol to close in on qualification.
[NEXT_CONCEPT]
Turkey has inaugurated a high-speed rail link between Istanbul and Ankara, slashing by half the seven-hour journey time between the two cities.
[NEXT_CONCEPT]
Shoppers across the UK are being encouraged to buy from independent stores on Saturday as part of a campaign to boost high streets.