BRASILIA—Allies of Brazil’s right-wing President Jair Bolsonaro are set to win leadership roles in Congress on Feb. 1, bolstering his standing but not necessarily his economic team’s reform agenda, analysts and politicians said. Rodrigo Pacheco of the center-right Democrats party, whom Bolsonaro has endorsed, is expected to easily win election as president of the Senate, with 55-60 votes in the 81-seat chamber, according to risk consultancy Arko Advice. Pacheco recently said he wouldn’t make a priority of privatizing Eletrobras, Latin America’s largest utility and one of the government’s biggest potential asset sales as it works to cut the fiscal deficit. He also disagrees with Bolsonaro’s policies easing environmental enforcement and gun sales. For speaker of the lower house, the right-wing Liberal Party’s candidate, Arthur Lira, has widened his lead over Luiz Felipe Baleia Rossi, of the centrist MDB party, who is backed by left-wing lawmakers pushing to spend more on …