Active Probe Targeting (TO:AR p97) states:
This bonus applies only to the unit with the Probe, unless
that unit is part of a C3 network, in which case the bonus is
passed along to other units in that network.
The question is, is that passing the bonus to another unit, or does the fact that the Indirect Fire rules (BMM p30) use the Spotter's LoS for terrain mean the Active Probe is helping the Spotter directly?