Compounds within the Yb-Ga binary system were prepared by direct melting of the elements, and their crystal structure was solved from single crystal X-ray diffraction. YbGa2 crystallizes in the hexagonal system, P6(3)/mmc, a 4.4527(2), c = 7.1969(3) angstrom, and YbGa4 is monoclinic, C2/m, a = 6.129(2), b = 6.1096(14), C=6.097(2) angstrom, beta = 119.05(5)degrees. A new compound of formula YbGa3.34 was identified in this system, and its crystal structure determined in the orthorhombic Immm space group, a = 4.2049(4), b = 4.3320(5), c = 25.691(3) angstrom. While atoms are fully ordered in YbGa2 and YbGa4, partial atomic disorder occurs in YbGa3.34 where gallium triangular units are found to substitute for some Yb atoms. The electronic structures have been calculated by first principles density functional theory methods using ordered models in supercells. Crystal structures and bonding therein are analyzed on the basis of gallium three-dimensional (3D) anionic networks and are compared with similar compounds. YbGa3.34 marks the boundary between layered and 3D intergrown gallium frameworks.