They are both Skins on the Winning Poker Network, there is at least one other skin, True poker, on that network.
In the case of WPN, the network handles the cash, so deposits and withdrawals are essentially controlled by WPN, not the skins. My experiences with BCP have been very good in regards to withdrawals.
Other networks have handled the cash aspects differently. Each skin might have been responsible for the money the players using that skin have in play. So, for example, when BCP was with the Merge network, BCP would have to deal with a committee of all the skins when it came to a once a month meeting to clear up the accounting issues. Merge at one point had at least 40 different skins, and we can't possibly imagine how insane those consolidation meetings must have been. BCP left Merge because they were so insane and their players suffered from that.
Don't try the funny stuff about multiple entries into the same game unless you are willing to lose everything you have invested in all involved sites. Every now and then we see posts about some site locking down a players funds, and we never get the whole story. The TOS (Terms of Service) for each site clearly states they don't have to give a player details about why it happened.
Don't be one of those players. online poker has evolved such that their software will know you are the same person, and if you agreed to the TOS to play there, and you have to, then you also gave them access to your system. Read the TOS for BCP and ACR if you don't believe this.