Martin,
Your setup is a little unclear but here's what I think is going on:
When running snoop with no filters will see everything on the VLAN you are connected to because it would be running in promiscuous mode. When you applied the filters, you told it to ignore everything except what is addressed to/from the other host. Had you started snoop and told it to filter on the host you were on, you should see only packets addressed to/from the host you are on, (not everything) which would be consistent.
Is that anywhere near what you are seeing?
Also remember that you will only see packets going to/from that remote host IF they pass through the VLAN you are snooping from.
James