If angels want to pool their money in an SPV I assume the SPV can invest in my fund?

Yes, however it's not a good idea to do so from a business perspective because:

1. Most SPV providers are not setup to do capital calls. As a result the costs involved in setting up an SPV that can manage capital calls is prohibitive. 
2. There is no benefit to the GP because every member of the SPV counts towards the 99 investor limit.
3. They can make investor relations more challenging.

@Mike Suprovici