The "dream pad" at 4:18 is - as written in the video - program Internal 90 "Zephyr". "Zephyr" is composed of the following two PCM samples as oscillators:
OSC1 = Pole (Pole is a notorious M1 sample
OSC2 = Strings (a string ensemble sample probably from the DSS-1 library
Of course these samples go through envelopes, filter, etrc, and then through "Concert Hall" and a "Symphonic Ensemble" FX in series.
The "sound around 6:00 with those looping bamboo-y type sounds" is the most famous M1 sound, the first preset that greeted you upon turning on the machine - Program Internal 00 "Universe". I personally think this sound in particular was responsible for selling so many units of this classic machine.
"Universe" has the two following PCM samples as oscillators:
OSC1 = Choir (a choir sample also probably originated from the DSS-1 library)
OSC2 = Lore (the most famous M1 sample, from the DSS-1 library
and of course these also go through envelope, pitch shifts, filter cutoff etc., and through "Live Stage" and "Stereo Delay" FX, in series.