to the OP the other guys are right at 155lb just getting bigger will help you with your bench but your only 16 you are probably not that bad a weight anyway and have plenty of time to grow.
I see your doing a 5 day split most likely a body part one, look in to one of the 5x5 programs for beginners, it may get you close to a 250 bench on your first run.
To steig,
bigtt is right, there are bugger all people strong at 150, while you are doing well putting on weight will get you stronger. You say that when you eat more your metabolism just adjusts, well really you just need to eat even more untill you put on weight. Trust me i know it costs a bit but if you want to get bigger and stronger thats what you got to do.
An example my new 125lb flat mate asked me to help him get bigger and stronger, i had him do 5x5 and said he needed to eat more. His answer was it doesn't work for him as he said he eats as much as me ( Im about 245lb) but still wont get any bigger, which was a load.
well too prove a point we go to maccas and he gets a cheese burger and small chips and is full. I get 3 large chips 5 quater pounders and 40 chicken nuggets and a few cokes, after that he realised he needed to just eat more. Which he did and its worked.