Do I need to install another Bonding bus bar in the disconnect

If you only have three wires coming from the meter, and four going to the "main" panel. Then you're going to bond the neutral in the disconnect enclosure, so the direct answer to your question is all 3.

If there's a grounding bus bar in the enclosure, you'll terminate the grounding electrode conductor (the other end of which is attached to the grounding electrode) at the grounding bar. Otherwise, you'll just pull it into the box.

Next you'll bond the box itself, by connecting a conductor from the box to the grounding bar (or grounding electrode conductor, if there's no bus bar). This may be done already, depending on how the bus bar attaches to the box. If the bus bar is bonded via the attachment method, you're done with this step.

You're also going to bond the service neutral in this box. This will be done via a bonding jumper between the neutral bus bar and the grounding bus bar, or by connecting a conductor between the neutral bus bar and the grounding electrode conductor.

You'll connect the grounding conductor going to the "main" panel, to the grounding bus bar or the grounding electrode conductor.

When you're done the service neutral will be bonded, so it should be isolated from the grounding conductor everywhere else in the building.

You'll end up with something that looks like this.

^{Click for larger view}

NEC requires the bonding electrodes be connected via an approved method if joined together outside an approved assembly like the main disconnects bonding lugs. In other words, you might have done it correctly assuming the main disconnect is actually in doors and not outdoors, and it had a free lug opened. If there were not any free lugs available then it would need to be secured via an approved method.

Adding two new ground rods ( 6 ft a part is Code ) would be ideal and leave the old one buried and unused. Though as mentioned by Ecnerwal it would not hurt anything to leave it connected. I say disconnect it as the next home owner will just be confused.

Edit

Additional info has came to my attention in that your drawing shows a box below the meter. This is typical of a main disconnect. Just to be clear, the panel inside would not be considered the main disconnect if there was already one outside. If this is the case then connecting the grounding electrode would only be acceptable at the main disconnect and not the panel inside.

Also, Code only requires one 8 ft ground rod if the minumin 25 ohms is met. It is easier to drive two ( Code says 6 ft a part ) and not bother testing if the 25 ohms is reached.