"Two women important to me"--the literal translation, and quite normal English--is marked (once again, arbitrarily) wrong.
That's because your sentence means something slightly different. The one in question features "của tôi" which means 'of mine' or 'my, mine'. It means "my two important women" or "two important women of mine".
If you wanted to say your particular sentence you'd go for something like: "Hai người phụ nữ quan trọng đối với tôi" where 'đối với' means 'to, towards, when it comes to'.