It depends on what you are using the system for. These are all older components, the processor and motherboard especially. If you are planning on playing games, this will not handle most mid range games and will not handle demanding games. For internet use (mini games, youtube, mail, etc) it will be fine, maybe a little sluggish as it only has 2GB of ram so your integrated graphics will be taking away from that RAM. If you are using it as a basic home theatre PC it should be fine for that. I would suggest spending 300 bucks on a Phenom II X4 quad core (90 to 120 bucks)with a lower to mid range motherboard (90 -120) with a low end dedicated graphics card (HD 6450 = 50 bucks) for a computer with much better performance. That way you can reuse all of your other components liker your case and power supply and so on. Your main bottlenecks though are your 2GB of RAM and your CPU.
That board supports phenom x4's, i would advice on getting that, will be a HUGE performance increase, also, get 4GB's of ram (DDR2) and this system would be able to play most if not all games with a better graphics card.
MB: ASUS M2A-VM HDMI
RAM: 2 GB
CPU :AMD Athlon 64 X2 4800+
HD: WD 320GB
Is there will be bottleneck ?
On high intensive cpu games there will be a bottleneck. Overall less cpu intensive games should just about play with 80-90%+ cpu usage. I would upgrade personally to a new machine with dx11 capabilities and quad core cpu to future proof yourself on gaming. I reckon desktop pc users should have a quad core phenom 2 x4 or core 2 quad at least.
The 9800 GT is still a decent card if you don't expect anything amazing compared to newer cards however it is much better than an 8500 GT. Actually the most demanding games list the 9800 GT as the minimum requirement and many console ports list it as the recommended so that card is still useful.