Short answer: no.
Medium answer: It would be significantly easier if you would just use the Donut theme. It already uses bootstrap, so you don't have to do anything there.
Longer answer: Using Bootstrap doesn't really mean just linking to a CSS file. Bootstrap has guidelines to follow when using it. SnowFlat is not really following those guidelines. So if you want to use SnowFlat you will have to adapt the whole theme to those guidelines. The result of doing that hard work will be similar to the Donut theme.
You haven't mentioned much about why you want to use bootstrap, but if you want it for the layout, you can use other libraries (like Flexbox Grid). If you want it mainly because of the styles I think you could try to extract the styles themselves from the Bootstrap files and generate some custom CSS with the ones you use.
