Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the B-q (q = n, s) mesons are shown to be in full agreement with experiment if a universal coupling alpha(HF) = 0.310 is taken in perturbative spin-spin potential. It gives M(B*) - M(B) = 45.7(3) MeV, M(B*(s)) - M(B-s) = 46.7(3) MeV (n(f) = 4), while in bottomonium Delta(HF)(bb) = M(gamma(9460)) - M(eta(b)(1S)) = 63.4 MeV for n(f) = 4 and 71.1 MeV for n(f) = 5 are obtained; just the latter agrees with recent BaBar data. For unobserved excited states we predict M(gamma(2S)) - M(eta(b)(2S)) - 36(2) MeV, M(gamma(3S))- M(eta(b)(3S)) - 28(2) MeV, and also M(B*(c)) - 6334(4) MeV, M(B-c(2S)) = 6868(4) MeV, M(B*(c)(2S)) = 6905(4) MeV. The mass splittings between D(2(3)S(1)) - D(2(1)S(0)), D-s(2(3)S(1)) - D-s(2(1)S(0)) are predicted to be similar to 75 MeV, which are significantly smaller than in several other studies but agree with the mass splitting between recently observed D(2533) and D*(2610).