In January I spent a week in Panglao, and then took the ferry and spent a week in Siquijor. I enjoyed both.
If you only have a week I would recommend Panglao. Balicasag island has been my favorite dive site so far in the Philippines. There are other sites as well, plenty to keep you busy for a week. Also more restaurant and nightlife options on Panglao. I recommend staying on Alona beach itself, so you don’t have to deal with trike rides, etc. I dove with Alona divers, they are run by locals and are very responsive to dms on Facebook. Two great spots for dinner away from Alona are Myst and the restaurant and Linaw resort. They both will require a short trike ride. If you hit Linaw around sunset time you get a great view of the sun setting over cebu and Dumaguete.
If you have the $$ stay at Henann on the beach, it was fantastic. Avoid the best western, their service wasn’t worth the price to me.
There are even more things to do on Bohol itself, but I haven’t even ventured off Panglao in the 6 weeks or so that I have spent total there over the years.
As for Siquijor, I stayed at the coco grove resort and dove with them as well. They were pretty unresponsive to messages asking for diving info beforehand, but once I was there they were very responsive. The resort and beach are very nice, close second only to Boracay in my opinion. I dove sites around that resort mostly, except for a day trip to Apo island. For you the trip to apo may not make sense since it is closer to Dumaguete and I assume you have been there already. I ate at the resort most of the time. There are options for restaurants away from the resort but they weren’t as easily found as on a Panglao. I hired a trike for one afternoon and took a tour around the island, there are some nice waterfalls and restaurants to visit.
Either place is a great option. The biggest issue I have had is having to leave, I was a bit sad my last day on Siquijor. I am coming back in September and doing 10 days in Cebu (Moalboal), and 10 more days at Dauin. I can’t wait.