No, no bloating here.
Keep in mind that minoxidil does not systematically 'bloat' peoples faces at all. What this myth is referring to is the fact that for a very small and stasticially insignificant sampling of people, minoxidil gave them facial edema which resulted in facial water retention.
I wouldn't worry about it. Some people are allergic to peanuts, some people can't hack the aspertame in Nutrasweet-sweetened beverages, and some people get facial edema from minoxidil.
Not saying that it can't happen, but the odds are rare, and if it does happen you can always quit, and try something else. It is reversible... quit the minoxidil, and the face stops retaining water and you're back to cool. In keeping with my listed analogies, do you let the fear of potential peanut allergies keep you from eating peanuts, or the fear of aspertame keep you from having a Diet Coke?
It's the best weapon we have to get our hair back. To let a miniscule fear like this keep you from trying it is not logical.