The evolution of the magnetic configuration inside an antiferromagnetically coupled GdFe/TbFe bilayer is studied at room temperature. For such system exchange-bias behaviors have been previously reported and are found to depend on the magnetic configuration above the blocking temperature 250 K. Here, the in-plane components of the magnetization are studied for different applied-field orientations. By comparing those results with a one-dimensional micromagnetic model the evolution of the interface magnetic configuration is well described. For the different applied-field orientations the magnetic behavior is found to be dominated by the formation of a magnetic twist at the interface which may adopt one chirality or the other.