Here is an example of using Texture.Repeat:
... create ...
... create texture
... render ...
int tileCount = 3;
spriteBatch.draw(tex, 0, 0,
tex.getWidth() * tileCount,
tex.getHeight() * tileCount,
However, this means you can't render your background in the same batch as the rest of your sprites. It also means you can't include the background texture in your texture atlas. The texture needs to be power-of-two sized (unless you are targeting NPOT-supported devices).
Ultimately it might be easier just to render the sprite multiple times in your batch (e.g. nested for loop). This allows you to include the background in the same batch as the rest of your sprites, and overcome the power-of-two issue if needed.
Anyways... The performance difference is pretty much negligible, so choose whichever is easiest for you.