The FSB only applies to the CPU, not the RAM. The RAM will operate at its listed frequency unless the motherboard is rated lower, in which case the RAM would run at the capacity of the motherboard.
Overclocking does affect the RAM, though, unless you put in a divider. You really don't have to worry about that... yet. If you hang around here you will eventually try overclocking, so we'll cross that bridge when we get there.