Step Grandparenting ~ support needed

I'm a step grandma to a 6 year old boy; my twin daughter's step son. She married last year and is now pregnant. I have a bio granddaughter the same age I have a strong bond with. My daughter has been angry with me and constantly berrading me for not doing enough for the grandson. I go to his concerts, bdays and include in all holiday gift giving. I raised 3 daughters and don't have much experience with boys.

My grandson has 2 other grandmas he has a close relationship with. I've been trying to form a bond with him but he's not interested; doesn't even say hi when I attend his events. My daughter is yelling at me for not doing enough, it's my responsibility for forming the bond (even though they only have him 1/2 time and are super busy with him when they do have him) and has been giving me the silent treatment stating I won't have a relationship with my grandbaby if I don't do better.

I have tried meeting with her and explaining how I need their help but would love to have that relationship. Any advice for working through this difficult and painful journey?

* [Post edited by GNHQ to remove names]