The Chinese equivalent phrase of 恋の予感
I will explain this in another view point :-) And I think it's better to put my conclusion first: 


  恋爱的预感 or just 恋之预感 is a perfect translation in Chinese.


Now, let's consider this interesting question:

Why is it said to be untranslatable in English?



  Koi No Yokan (Japanese): Koi No Yokan is a truly beautiful concept. It can defined the sense can have upon first meeting another person that the two of them are going to fall in love. In other words, it is the knowledge one has that he/she is going to fall in love with another person. This differs from the idea “love at first sight” in that it does not imply that the feeling of love exists, rather it refers to the knowledge that a future love is inevitable.


I think the essentials of the concept of 恋の予感 are


It should be a subjective sense, or, intuitive knowledge, about the future. So the word or phrase for 予感 should be neutral -- it implies neither good future nor bad future.
It should precisely describe the delicate situation that you know the love happens in the future but not at present.
Furthermore, in both Japanese and Chinese, 恋 is not equal to 愛. In Japanese, 恋 is


  特定の異性に強くひかれること。また、切ないまでに深く思いを寄せること。恋愛。


Which means a thing that one is attracted by another special person of the opposite sex, and thinking of him/her very deeply. And in Chinese, it is


  慕也。


Which means feeling attached to, or being reluctant to part. So, the meaning of 恋 can be considered the same in Japanese and Chinese. Intuitively speaking, 恋 is an immature kind of love, green but beautiful. For example, 恋人(こいびと) is not lover (愛人) but rather boy/girl friend (see goo辞書). It reflects one aspect of the eastern culture: being veiled to the emotion of love.


Thus, for Chinese, there isn't any culture barrier in the meanings of 恋 or 予感, besides, 恋爱的预感/恋之预感 makes sense in Chinese. So I said, 恋爱的预感/恋之预感 is a perfect translation.

For English, I found one translation on Weblio英語表現辞典:


  presentiment of a romance


This would be better than "premonition of love" because it takes Point 3 into consideration. But still, I find presentiment/premonition is often associated to unpleasant future. Maybe sixth sense is a better phrase, though it's informal.

EDIT

I check through the Roget's International Thesaurus for premonition, and find these entries:


premonition, presentiment; hunch, feeling in one's bones ... [generally implying something unpleasant, or being informal]
foreboding, apprehension, misgiving ... [implying something bad]
omen, portent, augury, symptom ... [they are not subjective sense]
harbinger, forerunner, precursor, herald ... [not subjective sense either]
ominousness, portentousness, portent ... [something bad]
inauspiciousness, unpropitiousness, unfavorableness ... [something bad]
auspiciousness, propitiousness, favorableness ... [something good]


It seems difficult to find a neutral and subjective and formal word to state 予感/预感 :(