Many people have reported that this works, but it is against the T&Cs, which require you be staying in one of the rooms in your reservation to get the points and perks. Recently someone started a thread stating he was surprised that his account was shut down for this. IMO it is not worth it to put your points and account at risk doing this.

Why not call the hotel and ask directly if this is acceptable? If they say yes, then you will not have to worry about getting caught doing something wrong. If you are unable to tell the hotel what you are doing than you pretty much have your answer on why you shouldn't do it.

Finally, recently I made a telephone reservation on my account for my sister and her family. We had been making other travel plans, it was late and this was the last reservation so she dropped off the phone. There was a note on the reservation indicating I would not be there. I did not have her cc or passport information which were required but was going to call back the next day with her to add the information. The hotel reached out within hours letting me know they needed her information which I explained they would get. Even though my sister is not Gold or Plat the hotel offered, without my asking, to grant them lounge access anyway. so honesty turned out to work well.