you can merge many textures together in material nodes, if your logo/text has an alpha so its background is transparent, you can use that to combine the two textures.
IE make a colour mix node, Add Diffuse texture to top colour slot, add Logo texture to bottom colour slot, and use the alpha from the logo file as the mix factor.
You can do the same thing with mixing 2 shader nodes.
If you don’t have a Alpha on the logo, you can also use a colour ramp node and create a mask from the colours of the logo and text
Here’s an example of how you can set it up as described.
https://www.dropbox.com/s/vfd7mxqiq0wa28s/logotexture.blend?dl=0
