I believe the most reasonable POD for this timeline is if Spain won in the Pacific during the Spanish-American War, where exactly would Spain's concession in China be? Maybe parts of Southern China the French don't get to first.
Defeating the USA requires decades of pod.
With regards to Chinese concession, you have to make it clear. Why does Spain need any concessions from China?
Good question. The markets in the concessions were already gone by that time. France occupied the markets of Guangdong and Fujian. Britain occupied the richest places, Zhejiang and Jiangsu, and the Yangtze in general. Germany 'held' Shandong, while Russia maintained control over Manchuria.
Sure, there's Beijing and Tianjin, but, honestly, who wants that? The powers would dislike it because it's literally where the emperor is, which gives (Spain) the most control over China.
By the way, how does winning the Spanish-American war lead to concessions in China? Is the Philippines supposed to serve as a naval base? Then what's the purpose of the concession if they can trade easily from the Philippines? (Remember, the purpose of the concessions in China was to trade!)
I see spain getting no benefits in getting something from China. Both Spain and China are or were the status quo in the region. And they were already trading and interacting hundreds of years without any land concession from one another before Russia, France, Britain, Germany even had a presence in the region.
Nor can I can connect the result of Spanish American war with Chinese concessions.
If Spain retained a strong position in the Pacific I could see them wanting a slice of China in the aftermath of the Boxer Rebellion. They could probably end up with whatever Italy or Austria received.
And they were already trading and interacting hundreds of years without any land concession from one another before Russia, France, Britain, Germany even had a presence in the region.
Italy, Austria, Belgium, the United States, and if I remember right, France, all did not get concessions.
Not true in Russia's case.
China's contact with Spain is only one century older than its contact with Russia.
Not true in Russia's case.
China's contact with Spain is only one century older than its contact with Russia.
They got concessions in Tientsin.