Prior to his own Tour de France win Thomas spent several years in a supporting role to Froome at Team Sky, which was relaunched as Team Ineos in May.
Froome missed this year's Tour after sustaining multiple injuries in a horror crash in the Criterium du Dauphine in June.
Thomas finished second behind Bernal in this year's race and he said in an interview that while the 22-year-old's rise was a source of frustration for him he had to put the team first.
"Yes, to be honest," the 33-year-old told the newspaper.
"When there are better riders (in the team) it's obvious. (Teamwork) is what you've got to do. It's a team sport and those two guys are special.
"Froome is the greatest Grand Tour rider of his generation, and Bernal... to win a Tour at 22, he could have 10 or 12 years of being super-competitive.
"But at least I'll always have that Tour win."
Thomas said he was fully focused on the Tour despite uncertainty over who will lead the British outfit in the race, which start on June 27 in Nice.
"We'll deal with it as we've done (in the past)," Thomas added. "When I won and Froome was third, when Egan won and I was second, the reason we both finished on the podium was that we were open and honest with each other.
"We pulled in the same direction, never chased each other down."
