Present work studies the effective rotational Hamiltonians and their vibration-rotational parameters for XH(2) and XH(3) type molecules near the local mode limit by including the diagonal matrix elements of coordinate operators when the bond anharmonicity is significant. An improved "alpha relation" is given for the local mode limit by taking the anharmonic bond oscillator wave function as the basis function. Then the rotational tunneling approach is extended to model the effect of nonzero interbond coupling for XH(2) and XH(3) type molecules, which provides a dynamical view of the rovibrational structure of the local mode states.