Neutron Spin Echo and Dynamic Light Scattering techniques are used for an extensive investigation of the bicontinuous phase in water/decane microemulsions. The dynamical behavior of different surfactant systems, decyl polyglycol ether (C10E4), C10E4 mixed with polyethylenepropylene/polyethyleneoxide amphiphilic block-copolymers-(PEPx/PEOy), and sodium-bisethylhexylsulfosuccinate (AOT) is investigated under comparable conditions. At scattering wave numbers q large compared to the inverse of the structure length scale, q(0)=2 pi /d, always stretched exponential relaxations proportional toe(q)(-(Gamma)t)(beta) with Gamma (q)proportional toq(3) are found, as predicted theoretically. The relaxation rate increases almost linearly as function of the bicontinuous structure correlation scale-xi similar or equal tod/2. The apparent bare bending modulus kappa determined by fitting theoretical predictions to the experimental high-q data yields values of about 1.3k(B)T-as inferred from previous small angle neutron scattering (SANS) studies and from other methods. The effect of increasing rigidity of the surfactant layers by anchoring amphiphilic block-copolymers, predicted theoretically and revealed experimentally in structural investigations, could not be clearly resolved due to its small influence on the dynamics. At structural length scales, the relaxation rate in water-oil contrast shows a minimum corresponding to the maximum of the static structure factor. At length scales much larger than the typical structure length the relaxation is single-exponential with a q(2) dependent rate. In this regime we find indications of the additional membrane interaction due to the presence of block-copolymers.