Well, I'm pretty sure a lot of people interpret Tinkerbell's charachter as in love or at least having a crush on Peter Pan in the original play/novel and maybe even in some of the more recent movies. Personally that's my headcanon but assuming fairies experience love in a different way that humans can't understand. In general I like it when non human beings have non human emotions but emotions nontheless and perfectly valid, just different. That gets me to the subject at matter.
My first question would be, have we been shown spren engaging in romantic and/or sexual relations of any kind among themselfs? It would strike me as odd for them to do this only with humans.
My second thought is that if they engage in any kind of relationship it's probably quite different from human relationships and almost all of them would experience feelings if at all, quite different from us. That being said, we have been told on several occasions that Honorspren are the ones that resemble humans the most and I think we have also seen them imitating human traits, so I think they're the most likely to engage in a humanlike relationship (possibly to a human) and to fall in love.
Now, for the specifics of Syladin. Like I said, it's a possibility, but I don't think we have been given much foreshadowing. Their relationship strikes me more like that of siblings. They care deeply for each other, look out for one another and share a very strong literal Bond; but I don't see much romance going on and no sexual tension whatsoever. If Syladin were to happen I wouldn't be shocked but I don't think is likely and would actually prefer if it didn't.
.....Howeeeeever when it comes to the ship, I think it's a great ship. It was pretty much unavoidable. Probability and possibility shouldn't be factors that prevent someone from shipping. If you enjoy it, Ship it!
I also think it's important to be respectful of other people's ships ( as long as those ships are respectful of the charachters we all love)
Wow that got rather long
Tl;dr:
1- I would prefer if spren didn't have emotions/relationships in the same way humans do.
2- If one type had, it would probably be Honorspren.
3- Syladin romance strikes me as unlikely but not impossible.
4- I read Syladin more like siblings.
5- Despite that, it's a great ship.
6- If you enjoy it, Ship away!