I've looked at many of the answers on this site to questions similar to mine, and I've seen a huge variety of answers. My situation is a bit more specific, so I decided to finally make a post and ask about it.
I applied to Pure Math PhD programs this year (for Fall 2021). I was accepted into two, neither of which were my top choices (they were on the safer side). My partner applied to PhD programs in a different field (not math) but we were not accepted anywhere together. We want to reapply to eachothers institutions this fall in order to be closer. In particular there is one school (call it Y) who is strong in my research area and is close to my partner.
Furthermore, the university whose offer I accepted (call it X) is not strong in my research area - there is at most 1 person who I could maybe work with, but even they are not really super in line with my research interests.
To summarize, I have accepted an offer at University X, and am entering the Phd program there this fall. I really want to reapply to school Y both in order to be close to my partner and because the research there is more in line with what I want to study. I also want to apply to some other top programs in my field, since, if I don't get accepted to Y, I would want to at least be somewhere with strong research in my field. My application for this fall will be notably stronger than my application last cycle due to more research and graduate coursework at my undergrad institution. Is re-applying this fall acceptable, or will it be viewed poorly (although I believe I have solid reasons)?
I am seeking advice on how viable this is since there are mixed responses for other questions. Any input is appreciated, but especially if you've experience this yourself or are perhaps a professor somewhere. Thank you!
EDIT: It's worth also nothing that X is "strong enough" in my area and I love the location, so I could be happy there. Just not ideal, really. In particular I came more into my professional interests a bit later in my undergrad, so at the time of applying I wasn't firmly in one area of research (hence, I'm realizing a bit late that it's a little bit of an awkward fit at X).