AFAIK, there is no option to set tile sizes directly from the command line.

However, you could use the [python api][1] to do this, and execute a python script in blender from the command line. (see [this question][2])

To set tile sizes from python, you can use  
[`bpy.context.scene.render.tile_x`][3]
and [`bpy.context.scene.render.tile_y`][4].

Tile order can be set with `bpy.data.scenes["Scene"].cycles.tile_order`.  
This can be set to `'CENTER', 'RIGHT_TO_LEFT', 'LEFT_TO_RIGHT', 'TOP_TO_BOTTOM',` or `'BOTTOM_TO_TOP'`

An example script to set the tile size to 32x32 and set the order to `Right to Left`:

    import bpy
    
    for scene in bpy.data.scenes:
        scene.render.tile_x = 32
        scene.render.tile_y = 32
        scene.cycles.tile_order = 'RIGHT_TO_LEFT'
Note that it loops through each scene to set these properties globally. (see [this][5])  
You can run this from the command line with

    blender --background /path/to/my.blend --python /path/to/script.py --render-anim
    # or the short version:
    blender -b /path/to/my.blend -P /path/to/script.py -a

Borders:
==
AFAIK, it's not possible to tell blender to only render n amount of tiles, when n is less than the total tiles needed to render the complete image.
(blender does print a new line to stdout for every tile that is rendered, so you might be able to make some hack to stop blender once n tiles have been rendered, but I don't know if you could save output.)

Because of this, you might be better off using the [*Render Border*][6]; this will allow you to exactly define what section of the image to render. 

You can enable border with `bpy.data.scenes["Scene"].render.use_border = True`

The border region is defined with four values between `0` and `1` where `0` is the left or bottom edge of the camera, and `1` is the right or top edge.

You can set the [min and max xy values for the *camera* border][7] with

    bpy.data.scenes["Scene"].render.border_max_x
    bpy.data.scenes["Scene"].render.border_min_x
    bpy.data.scenes["Scene"].render.border_max_y
    bpy.data.scenes["Scene"].render.border_min_y

You may also want to enable *Crop to border* with `bpy.data.scenes["Scene"].render.use_crop_to_border = True`

Note that to set the *viewport* border you must use [this][8] instead, but you most likely are interested in camera border as viewport border is only relevant for using the realtime rendering feature. (see [this post][9] for more info)


  [1]: http://www.blender.org/documentation/blender_python_api_2_68_5/contents.html
  [2]: http://blender.stackexchange.com/questions/1365/how-can-i-run-blender-from-command-line-or-a-python-script-without-opening-a-gui
  [3]: http://www.blender.org/documentation/blender_python_api_2_68_5/bpy.types.RenderSettings.html?highlight=tile#bpy.types.RenderSettings.tile_x
  [4]: http://www.blender.org/documentation/blender_python_api_2_68_5/bpy.types.RenderSettings.html?highlight=tile#bpy.types.RenderSettings.tile_y
  [5]: http://blender.stackexchange.com/a/3062/599
  [6]: http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Output#Dimensions
  [7]: http://www.blender.org/documentation/blender_python_api_2_68_5/bpy.types.RenderSettings.html?highlight=border_max_x#bpy.types.RenderSettings.border_max_x
  [8]: http://www.blender.org/documentation/blender_python_api_2_68_5/bpy.ops.view3d.html?highlight=border#bpy.ops.view3d.render_border
  [9]: http://blender.stackexchange.com/a/2023/599