As part of Hercules Invictus, I'm in the process of starting up separate Orders of Apollo and Dionysos. I'm currently still working on the framework and ideas for starting out, but essentially it'll be for all types of devotees with optional subsets involving the gods' mysteries.
Each Order will initially focus on the worship and experience of the god through examining things such as Homeric and Orphic hymns, experimenting with various rituals to the god, and performing good deeds on behalf of each deity. Of course each Order will have different things to offer that are specific to the god, and in the end it'll be something of a combination study/ritual/worship group.
The idea will be that people who contribute to the Order can go on to experience the Mysteries if they so desire, or assist in developing further the curriculum and requirements for each Order. Either way only those who contribute will be counted among our ranks. I will not be requiring people to write books or get PhDs, but I will note if people join and sit around doing nothing while taking credit for just being in the organization.
If you have any interest in the above for either or both gods, please let me know either here or via email.Edit: I'll be using the following public lists for each of the Orders until the first initiates for each have gone through the first stage:
Once there are people who have gone through the first stage, I'll create a separate emailing list for each and will continue the first stage on these lists for anyone who is interested who wasn't able to do it before or wasn't on the list prior.