In column C why don't you just keep it simple and put the Spread Prediction based on the Away team at all times?

For example...
In row 5 you have Falcons and Eagles, with Falcons +3.5. In C5, just put 3.5.
In row 6 you have Bills and Ravens, but show Ravens -7 (which would mean Bills at +7, yes?). So basing it on the Away team, you'd put 7 in C6.

By just using numbers, you can then probably figure out the math needed in each row to use the conditional formatting.