It all depends. When I'm towing a glider that is in the low-tow position I'm pushing the stick forward and believe that the resultant force from the tailplane & elevator is probably upwards. When the glider is in the high-tow position I'm pulling the stick back and believe that the force is downwards.
The tow rope tension imparts a pitch moment towards the glider position. Thus if the glider is below the tug, the moment will be nose up and forward control column pressure will be necessary for the tug pilot - and vice versa if the glider is above the tug.
As the magnitude of the tension is rarely constant, it will often be necessary to cope for out-of-trim situations with residual control column forces.