The lasting appeal of the ``next-to-harmonic" and ``first unsolvable" quantum bound-state models with central polynomial potentials derives from their broad phenomenological applicability. For this reason one encounters numerous attempts at construction of reliable interpolation/extrapolation closed formulae for the energies, among which the most valuable ones offer the approximative or strict lower and/or upper estimates. The paper in question offers and discusses a number of new and/or most updated formulae of this type which are mainly based on the idea of sophisticated semiclassical approximation. Particular attention is paid to the family of the two-term potentials of the so called anharmonic oscillator. MR2384005 Katatbeh, Qutaibeh D.; Hall, Richard L.; Saad, Nasser Eigenvalue bounds for polynomial central potentials in $d$ dimensions. J. Phys. A 40 (2007), no. 44, 13431--13442. 81Q10 (35J10 47N50)