Render to RenderTexture in android/gles (plugin)

I am attempting to update a texture via a plugin in Unity. My first attempt was using a Texture2D, and while it works fine in android, on windows d3d11 there is no way to lock the buffer, and it crashes. So I found a solution, by using a RenderTexture, I get a dynamic type texture, and can map/unmap it to lock my buffer and it no longer crashes.... Except my rendering in gles no longer works. I don't get any error, it just doesn't write to my texture for some reason.

Here is a sample of my gles code (it was heavily inspired from an example I found online, as I am not super familiar with gles. Note that this all works fine if I use a Texture2D, but fails silently if I use a RenderTexture. I removed most of the error handling code to simplify readability, but I do normally check for glErrors everywhere, and no errors occur):

 int texW =m_frameW;
     int texH = m_frameH;
     int dataSize = texW * texH;
 
 
     bool singlePBO = false;
     if(!testCreated)
     {
         glGenBuffers(2, pboIds);
         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pboIds[0]);
         glBufferData(GL_PIXEL_UNPACK_BUFFER, dataSize, 0, GL_STREAM_DRAW);
         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pboIds[1]);
         glBufferData(GL_PIXEL_UNPACK_BUFFER, dataSize, 0, GL_STREAM_DRAW);
         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
         testCreated = true;
     }
 
     static int index = 0;
     int nextIndex = 0;                  // pbo index used for next frame
 
     // "index" is used to copy pixels from a PBO to a texture object
     // "nextIndex" is used to update pixels in a PBO
     if(singlePBO)
     {
         // In single PBO mode, the index and nextIndex are set to 0
         index = nextIndex = 0;
     }
     else
     {
         // In dual PBO mode, increment current index first then get the next index
         index = (index + 1) % 2;
         nextIndex = (index + 1) % 2;
     }
     // bind the texture and PBO
     glBindTexture(GL_TEXTURE_2D, (GLuint)txId);
     glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pboIds[index]);
 
     // copy pixels from PBO to texture object
     // Use offset instead of pointer.
     glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, texW, texH, (useAlphaChannel?GL_ALPHA:GL_RED), GL_UNSIGNED_BYTE, 0);
     if((err = glGetError()) != GL_NO_ERROR)
     {
         SAL_FUNC_DEBUG("Error trying to copy texture, switching channel");
         useAlphaChannel = !useAlphaChannel;
 
         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, texW, texH, (useAlphaChannel?GL_ALPHA:GL_RED), GL_UNSIGNED_BYTE, 0);
 
         if((err = glGetError()) != GL_NO_ERROR)
         {
             SAL_FUNC_DEBUG("Switching channel didn't help... you're screwed");
         }
     }
 
     // bind PBO to update pixel values
     glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pboIds[nextIndex]);
 
     // map the buffer object into client's memory
     // Note that glMapBufferARB() causes sync issue.
     // If GPU is working with this buffer, glMapBufferARB() will wait(stall)
     // for GPU to finish its job. To avoid waiting (stall), you can call
     // first glBufferDataARB() with NULL pointer before glMapBufferARB().
     // If you do that, the previous data in PBO will be discarded and
     // glMapBufferARB() returns a new allocated pointer immediately
     // even if GPU is still working with the previous data.
     glBufferData(GL_PIXEL_UNPACK_BUFFER, dataSize, 0, GL_STREAM_DRAW);
 
     GLubyte* ptr = (GLubyte*)glMapBufferRange(GL_PIXEL_UNPACK_BUFFER,0, dataSize, GL_MAP_WRITE_BIT);
     
     if(ptr)
     {
         // update data directly on the mapped buffer
         memcpy(ptr, m_frame.data(), dataSize);
         glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER); // release pointer to mapping buffer
     }
     
     // it is good idea to release PBOs with ID 0 after use.
     // Once bound with 0, all pixel operations behave normal ways.
     glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 

Does anyone know if a RenderTexture is considered as a gl Texture2D? or maybe it is a FrameBuffer or something? Unity were nice enough to provide a plugin example using a texture2D, but nothing with RenderTexture.

Any help would be greatly appreciated at this point.