You asked the Teacher, "what she's noticed."
Well, to me... that is not the question to ask.
Because, probably the Teacher does not see nor know, what is going on during lunch. She is not a lunch Monitor.
So, you need to re-frame your question to her.
And be, clear.
TELL her, that your son came home on the verge of tears... tell her what happened and why. And TELL her, that that boy regularly.... is "pretty tough" on your son, only. ONLY on your son. Even the other kids say so.
You need to make things clear, when questioning the Teacher.
And, note down what your son told you.
AND yes, earning points... can make some kids, very bossy and bully like because all they are thinking of is themselves. Not the "table" as a Team. Point earning, is done to engender "Team" behavior, per table cluster. NOT selfish behavior. THAT... is the point to make with the Teacher.
So, that the Teacher, can speak to that bossy Boy, and correct him/his attitude. Because, the boy is taking this point-earning, in the wrong manner....and he is creating antagonism between classmates. Not team behavior.
THAT is what I would do.
My kids' Teacher, ALL, will talk to the classroom as a whole... and correct or clarify... any misconceptions or attitudes, in their students. So that... the point-earning, is understood.
(my kids' classrooms, has these "point earning" per table clusters as well. AND it is done, in order to build TEAM behavior. NOT selfish behavior. SO, when/if, a kid on my child's table is being incongruous or bossy to the others on that table... the Teacher, DOES correct that child. Because, it does not nurture the table as a Team, but divides, it.) And the whole point to point-earning per table cluster... is that the kids work as a TEAM... not singling out each other or getting points for themselves.
Your son and that boy do not have to be best buddies. BUT, as a classroom or table.... "team" effort is what is expected, in school.
It is not for "you" to correct. And you cannot expect your 2nd grade son, to correct it by himself.
The Teacher needs to know and correct it. Because that bossy Boy... is creating rifts at their table. And, not heeding to the whole lesson of "team" behavior for that table cluster.
I am a Lunch Monitor at my kids' school.
And the kids have table clusters too and point earning PER table cluster. As a Team.
I know very well... what the "lesson" is supposed to be about this whole thing. It is not so the kids compete individually with each other... it is for teaching TEAM... cooperation. And how to get along with others.
You... ALSO teach your Son, how to speak up and what the point is, of table point-earning.