I'm a CX member and can only speak as such.

In terms of bags, yes, as a Ruby (CX SL) member you can check 2 bags 23kg each for free when travelling on any AA FLT. However, if you are connecting to a CX trans-Pacific FLT, you are entitled so even if you were not a member.

For preferred seatings on AA, you are entitled to as well. However, AA.com doesn't support this. You will have to request a specific seat number from where you make the booking (TA, CX, or whoever makes the booking for you).