Hmmm. I have a slightly different experience to you. I am bilingual - English/Afrikaans - though my Afrikaans was never a language I used a lot and I have a very poor grasp of it in comparison.
This has led to something interesting - if I try to think in Afrikaans, I notice a distinct difference in my thoughts. Normally, my thoughts take the form of an internal monologue (almost, but not quite, exclusively). If I try to think in Afrikaans, which has a different grammar (and importantly, a different word order) to English, then I get the distinct impression of parts of my thoughts queued up and waiting for their part of the sentence to happen. This tells me that there are more complicated things going on inside my head than I had previously thought.
...though interesting, I have not as yet found any practical use for this knowledge.
I don't know Afrikaans, but Russian is very much unlike English in a lot of things - most notably, the order of words in a sentence usually plays next to no role whatsoever in terms of actual meaning (you may sound somewhat posh or dramatic if you randomize it too much, but Yoda still sounds pretty normal in all Star Wars Rusian translations I know). Given all that, I don't feel anything like you describe when I think in Russian.
Another month, another rationality quotes thread. The rules are: