RAM type/speed isn't really determined by the processor; rather, it depends on the motherboard, since it provides the electronics (chipset) and physical specifications (RAM slots) required by the memory.
133Mhz SDRAM is 133Mhz SDRAM, no matter if it's being used in a PIII or P4. Because of its age, however, I'd say it's much more probable to find it in a PIII system than in a P4 system (P4 systems generally use DDR SDRAM).
Hope this answers your question. If you need more info, please say so and I'll be glad to help.