Given a Lie group G, a compact subgroup K and a representation τ ∈ K, we assume that the algebra of End(Vτ )-valued, bi-τ -equivariant, integrable functions on G is commutative. We present the basic facts of the related spherical analysis, putting particular emphasis on the rôle of the algebra of G-invariant differential operators on the homogeneous bundle Eτ over G/K. In particular, we observe that, under the above assumptions, (G, K) is a Gelfand pair and show that the Gelfand spectrum for the triple (G, K, τ ) admits homeomorphic embeddings in C n .In the second part, we develop in greater detail the spherical analysis for G = K ⋉ H with H nilpotent. In particular, for H = R n and K ⊂ SO(n) and for the Heisenberg group Hn and K ⊂ U (n), we characterize the representations τ ∈ K giving a commutative algebra.2010 Mathematics Subject Classification. 43A90, 43A85.