I believe that is too much imagination for now. For sure they will be evaluating the performance from Renault at Bahrain, but I don't believe they are considering an other supplier just after one bad test. It's also a waste of very precious time in the short run: they have issues that need to be cured now; the top management isn't putting in time and effort now to check if the grass is greener at the neighbours.
Chances are good renault will have it's engine in tip top shape by 2015, while red bull has all the relevant data. No team is going to throw that away (well, except mclaren...) to take risks with a new supplier, with which they are going to have new issues with.