Generally no right for paying taxes but possibly could give an interest.
This is not a comprehensive answer and it is impossible to provide a meaningful response without a consultation.
Wow, you're paying someone else's property taxes without any agreement as to why you are doing that? Sorry to say, without more information that could possible give you some rights by way of an agreement, just paying the taxes alone will not do it; however you may have a claim against the actual property owner for reimbursement if it was understood this would be some kind of loan or such. Small claims in Ca goes up to $10,000. If you are just paying out of the goodness of your heart, with nothing more than a hope it could lead to something, while you are a good man or woman, but sorry to say no rights to the property.
The foregoing is for informational purposes only and may not be relied on as attorney-client advice.
The only situation where paying property tax may lead to an ownership interest may be in an adverse possession action (depends on the state). In general I have not come accross a situation where paying someone elses property tax would lead to an ownership interest. That being said you should consult with a local Attorney that handles property tax matters.
No attorney / client relationship established. The answer is for discussion and general information only. The lawyer had not reviewed any documents or contract prior to the above comments.