The 51-year-old was not short of confidence in Barca's size and stature as a club, though he did admit that the changing landscape of European football could make it more difficult for them to compete in the future.
And Bartomeu cited Manchester City and Paris Saint-Germain as prime examples of teams who have no limits on what they can spend.
Barcelona host Man City at Camp Nou for the second leg of their last-16 Champions League tie on Wednesday and Bartomeu's comments could be perceived as a veiled jibe at City's high levels of spending in recent years.
"The emergence of Manchester City and Paris Saint-Germain has made things more difficult," he told BBC Sport.
"In the last few years some clubs appear that are owned by one person that sometimes have unlimited resources and at Barca we don't have unlimited sources.
"Of course we are a very big club. We are the biggest club in the world but when we compete with unlimited resources we have to find other ways, other strategies."
Meanwhile, the Barca supremo also backed current coach Gerardo Martino amidst criticism of the club's poor recent form.
A 1-0 loss at Real Valladolid last weekend made it two defeats in three La Liga games for the Spanish champions - something that would have been unheard of in seasons gone by.
"Martino has a contract with us until June 2015," Bartomeu told radio station Cadena Ser. "We would like Martino to remain with us next season."
"We hope he will remain with us for a long time. He is eager to do things well and win."