By Rosalba O’Brien and Antonio De la Jara SANTIAGO (Reuters) – Chilean President Michelle Bachelet has chalked up her first political victory since returning to power as Congress approved a key tax reform, but she faces an uphill struggle to make good on other promises. On Wednesday evening, Chile’s Congress, which is controlled by allies of the center-left Bachelet, approved a bill that raises corporate taxes in order to pay for an ambitious package of social reforms, including a planned overhaul of the education system. Some have yet to be submitted to Congress, while others are embroiled in doubt and debate.