Pair pho bo (a soup with beef typically) with a glass of wine that can hold up to the hearty protein. For Pho Bo with beef, a medium body Merlot or Pinot will do great. Don't get anything too bold like a Syrah or Cabernet Sauvignon or else you'll lose all the subtleties of flavor in the soup.
Pho Ga (a.k.a. Chicken Pho) goes really well with a crisp white wine that isn't too sweet. Try pairing it with a cool glass of Sauvignon Blanc or Chenin Blanc for the perfect pairing.
Expect seafood pho to be slightly sweeter. Typically, it's made with white fish or lobster. A good wine pairing would be an unoaked Chardonnay or Muscadet. You want a wine that cuts out the spice and brings out the sweetness in the soup without overpowering it.
If you're going for a vegetarian meal, veggie pho is still just as delicious as the other pho types. Typically, it will include mushrooms and pairs nicely with an oaky Pinot Noir or lightly oaked Chardonnay. Mushrooms are nice because they pair so well with either red or white because of their earthy, but light flavors and textures.
Always think before you pair a wine with pho. If you choose to drink any wine with pho, you risk ruining the delicious experience of enjoying this uniquely spiced soup. Choose your wines wisely and you'll be happy you did!