Often in my shul a man who traveled from Israel or Asia to the US will bentch gomel. I have never once seen a women bentch gomel for anything other than giving birth. I'm not sure if this is just my personal experience so I am asking if women in fact bentch gomel less often than men, and if so why?
The answer is Shulchan Aruch Orach Chayim siman 219, sayif 1, in the first paragraph of Magen Avraham and other commentaries.
בכ"ה תמה למה אין הנשים מברכות ברכה זו ואי משום דבעי י' הא דבדיעבד סגי בלא י' ולכן תברך בפני איש א' או בפני נשים עכ"ל ואפשר שמנהגן מפני שס"ל שברכות אלו רשות:
(loose translation making use of Baer Heytev and Mishna Berura) The Sefer Knesset Hagedola expressed his astonishment why women don't bless Hagomel. I f the problem is the need of minyan, and by modesty it's not recommended for a woman to talk in front of a male audience, so she can bless alone. The best is to bless before a female audience containing one man (one of the 10 need to be a man) . Magen Avraham said that the reason that they don't bless it is because this kind of blessing are not really a duty.
so I am asking if women in fact bentch gomel less often than men
--> Yes, the Knesset Hagdola made the same observation.
and if so why?
--> First Teruts: because of modesty they bless it without minyan; second Teruts: they bless before an audience with a majority of women, third teruts: the Ykar hadin is that blessing of this type are not a duty, and they don't bless at all.
The mention of a minyan is from the Gemara itself Berachot 54b:
Abaye said: And he must utter his thanksgiving in the presence of ten, as it is written: Let them exalt Him in the assembly of the people. Mar Zutra said: And two of them must be rabbis, as it says, And praise Him in the seat of the elders. R`Ashi demurred to this: You might as well say [he remarked], that all should be rabbis! - Is it written, 'In the assembly of elders'? It is written, 'In the assembly of the people'! - Let us say then, in the presence of ten ordinary people and two rabbis [in addition]? - This is a difficulty.
@Double AA noted tha even t if the answer is the above, women don't know it generally, this is a Kashia for him. Right but I think that poskim searched to understand the minhag that women don't say Hagomel. The possibility to regard Hagomel as facultative or to bless Hagomel without minyan apparently contradicts the Gemara, we need to understand more the statements of the poskim. I believe that I didn't invented nothing.