Lionel Messi and Neymar scored twice, while there were also goals for Pedro and Gerard Pique as the Catalans put their hosts to the sword.
There was no place for Luis Suarez in Luis Enrique's starting XI but it mattered little as Barca ensured the gap between themselves and leaders Real Madrid remains at just a single point.
"We have the best attack in the world," Bartomeu said after the game. "We demonstrated that again in this game. We have a very powerful attack."
Messi's two goals took his tally for the season to 31 strikes in 31 games for club and country, but the Barca chief is adamant the Argentine isn't motivated by personal statistics.
"Messi plays for the team, he doesn't look at statistics or goals," he added.
"We are improving in the second half of the season and we are growing in confidence at an important part of the campaign."
Barca are back in action again on Wednesday when they face Atletico Madrid in the second leg of their Copa del Rey quarter-final tie having won the first leg 1-0 at Camp Nou last week.