Flowers

This is a matter of personal preference, there is no right or wrong answer. I personally prefer a cohesive look, but you’re right that guests won’t likely compare your bouquet to the reception decor.

I agree about guests not remembering your bouquets to compare the centerpieces to. Their focus will be switched over to your entrance, food, music, etc.

Do what you like! While most would go for matching, there is no official rule book. Its your day, so make it your own

I like a cohensive look rather than two different looks as I feel it would look disjointed. If you plan on carrying your bouquets or having the bridesmaids carry their bouquets into the reception area then you will have two different styles together. During our introductions we carried our flowers into the reception. My bouquet was used as my centerpiece for our sweetheart. While your guests probably wouldn't care I would think two different looks for seen strange and you would have to plan even more than you went with all of the same flowers.

How different will the bouquets and centerpieces be? Could they be considered complementary, or have any similarities?

Similar to the PP, I'll be laying my bouquet on our table at the reception (haven't decided what we're doing with the bridesmaids' bouquets yet). Our centerpieces don't have any floral beyond some eucalyptus/greenery, so they'll be pretty easy to work with. I'd just consider what you'll be doing with the bouquets during the reception.

Even if your bouquets and centerpieces don't look anything alike, I highly doubt people are going to really notice or care. It comes down to your preference.

I think it would be fine for them to not “match”

It doesn't have to match

I think that'll be fine! Not everything has to match to a tee