The iPhone came about 6 years after the iPod, which itself was wildly successful so certainly Apple was nowhere near bankruptcy when the iPhone launched.

They also weren't on the brink of bankruptcy when they made the iPod either - the original iPod launched in 2001 which was ~4 years after the Microsoft investment you mention (that happened in 1997).

Apple actually launched the highly successful iMac (the colourful ones) back in 1998, and it was arguably the success of that which restored Apple to having good profitable. I.e. it was already well on the 'up' by the time the iPod launched and propelled them to even greater financial success.