In this work, thick Ga0.485In0.515As1-x Bi (x) epitaxial layers were grown on semi-insulating (100)-oriented InP:Fe substrates by molecular beam epitaxy. For investigation of the buffer layer influence on Ga0.485In0.515As1-x Bi (x) properties, two compositions of buffers were used: lattice matched to InP:Fe substrate-Ga0.477In0.523As, and lattice matched to bismide layer-Ga0.434In0.566As. The buffer layer thickness varied from 100 to 650 nm. Three hundred-nm-thick bismide layers were grown at 280-300 A degrees C substrate temperature with growth rate of 300 nm/h. Structural investigations of omega - 2 theta rocking curves measured for (004) reflex revealed the incorporation of Bi up to 3.6% in quaternary compound. Bismide layer surface inspection by atomic force microscopy demonstrated roughness of about 0.65 nm. Despite the fact that structures are 100's of nanometers thick, reciprocal space mapping measurement demonstrated that both the buffer and the bismide layers are fully strained. It has also been revealed that rapid annealing at the temperature range of 550-700 A degrees C of Ga0.485In0.515As1-x Bi (x) layers improves photoluminescence intensity, extends carrier lifetime and enhances electron mobility.