50美分派对 also finds no results on Bing, but plenty of results on Google.
So it's not just tank man. The word filter is active for all search terms that are blocked in china.
50美分的军队 I think is another way of writing it: it shows only 3 images on bing, which all look like ads for Coca Cola.
If you look closely at the Wikipedia article, you'd see that the text in the infobox is 五毛党 (五 wǔ 5, 毛 máo 0.1 piece, 党 dǎng political group [No relation to Daniel G]).
What you wrote is 50 美分 (měi fēn American cent) 派对 (pài duì fun get-together.)
I get Bing results for both, but the "American cent" ones are all about the rapper.