In the performance of thermoelectric devices, one of the important parameters determining high efficiency is the coefficient of the thermopower, which is called also Seebeck coefficient. Investigations of the thermoelectric properties of bismuth and its alloys often indicate an increase in the coefficient of thermopower under magnetic field application. In the case where the influence of the magnetic field is used, for a correct evaluation of the contribution in the figure of merit of the Seebeck coefficient, one should carefully analyze the behavior of the latter under applied field.  In the particular case of bismuth, magnetothermoelectric performance shows dependence not only by the thermopower, but also by the anisotropy factor. At the same time, anisotropy factor in Bi provokes the appearance of a ―reversal‖ effect of the thermoelectric power that occurs in the magnetic field for certain crystallographic orientations. This phenomenon, first experimentally observed in Bi, was designated as Umkehr effect [1] and defined as the difference between the thermoelectric voltage when reversing sign of the applied magnetic field. Analytic expressions for the thermomagnetic power tensors derived from the phenomenological transport theory in the relaxation time approximation show that arising asymmetry in the thermopower is due to off-diagonal components that contain even and odd terms as functions of magnetic field [2].  Here we present the results of the measurements of the transverse magnetothermopower and magnetoresistance in thin bismuth wires at 4.2 and 77K. The shape of the angular dependence of the transverse magnetoresistance measured in magnetic fields rotated within the trigonal-binary plane perpendicular to the wire axis is similar to the data for bulk Bi crystals of the same orientation only with a small deviation in a narrow range of angles close to the trigonal axis.  Investigations under uniaxial strain revealed a strong change in the anisotropy of magnetoresistance at large deformation rates. Simultaneously we observe a drastic decrease in the transverse magnetoresistance when magnetic field is along the trigonal axis. The manifestation of the Umkher effect is found on the angular dependence of the transverse Seebeck coefficient in the non-deformed Bi wires. Under the application of strain, the change in the values of the transverse Seebeck coefficient is observed to occur in different ways along different crystallographic directions. Analysis of the components of the magnetothermopower tensor makes it possible to reveal fine details of the Fermi surface in the process of uniaxial deformation. The evolution of the magnitude of Umkher effect in the transverse Seebeck coefficient under strain is explained in the frame of phenomenological and band-structure calculations for semimetals.