Uh, the same difference between a 97 and 99 year old, 07 and 09 year old and anyone else with a 2 year age difference?
I'm definitely not in the late 80s born age range, but I could give some input from a more general standpoint.
People born in 87 experienced the 90s in its entirety from young children to young tweens. They, along with '86ers and '88ers are quintessential 90s children- meaning they likely remember the 90s decade from start to finish. An '89er, on the other hand, is unlikely to remember the early years of the decade except '92 or maybe '91. In fact, I should maybe change the '88ers and place them with the '89ers. The chances of an '88er not remembering '90 is equal to the chance of a '89er not remembering '91- and '90 is a part of the 90s after all.
However, when it comes to teen years and youth, late 80s babies all graduated/came of age around the mid-late 00s, so those life years wouldn't be all that different.
If you're asking the question for relationship purposes, nothing should really be stopping you, age wise. Obviously now there isn't really a difference between yourself, an '89er, and a '87er. two. Y'all are both gonna be 30 and 32 this year, the same 'decade age'. People 2+/- years your age are full adults well into the work world, starting families (or thinking of doing so). In terms of pop culture, you guys are well out of its audience (b/c Gen Z has currently taken that place) but as Millennials, you guys are today's pop culture leaders for Generation Z.
I can't really speak for you guys , however, because as I've stated, I am not part of this cohort. I'm making assumptions based on past connections between 90s and 00s borns, when they grew up, came of age, etc (since that's my cohort).